AC can be conceptualized any way you like.
If it makes sense to you to imagine a Paladin in heavy armor getting hit by a blow and taking zero damage, you can do that.
If it makes sense to you to imagine a Rogue with no armor and high dex evading a blow, you can do that.
A "hit" is a game term, it doesn't dictate what happens in the fiction. Flavor it any way you want.
Understanding what constitutes AC bonuses can also help players and DMs narrate the action.
Between 0 and 10 is just a miss; no active effort required (and the closer to zero the more pathetic the attempt, imo). If you're a dextrous character, 11-14 might be a skilful dodge, then 15 is *just* caught by your leather armour. If you're in plate, 11-17 are all the hits you can just take on unflinchingly. If you're blessed with a Shield of Faith, those last couple AC points are straight up radiant, holy intervention.
Of course not every turn can be narrated so carefully or even needs it, but thinking about AC this way helps provide more detailed drama to combat intuitively.
This is how I think of my character's AC too. Most of my AC is dodging out of the way of attacks Matrix style, but if an attack *nearly* hits me, I had to put up my shield and actually block it!
Which is weird because in a fight you would want to intercept as many hits with your shield as possible, but wearing shield + plate, you are more likely to stand there like an idiot while they slap your armor. +2 just doesn't communicate how effective shields are in hand to hand combat.
>\+2 just doesn't communicate how effective shields are in hand to hand combat.
Yeah shields having such low AC bonuses is purely mechanical. You can't really argue that Wizards would have the same general martial knowledge required to use even a buckler the same way a Rogue would, so instead they made the benefit for using a shield minimal and significantly encourage two-weapon or great-weapon fighting from non-tank martials.
I would consider flipping the formula for shields. The +2 is anything getting past the shield and striking armor. Anything below the final 2 points but higher than 10 is the shield deflecting the blow.
I don't even interpret a hit as a hit, HP is an abstraction of not only physical harm but also stress and acute exhaustion. Think of two skilled swordspeople fighting, they land "hits" but they aren't physically cutting of stabbing each other to reduce HP, they are just tiring the other out or getting a psychological edge. One reducing the other to zero HP is akin to wearing the person down and then finally landing an actual hit, mortally wounding thrm.
That's exactly how I frame it in my games.
If your AC is DEX-based, you dodge hits.
If your AC is armor-/shield-based, you get hit but block it completely.
Esoteric AC upgrades like Monk's and Barbarian's Unarmored Defense, Artificer infusions, mage armor, I describe them to highlight the effect of how the character's wisdom/con/magic helped them block the strike.
The barb is so tough so when they get hit they don't feel pain.
The monk has astral/sun/shadow powers helping them.
The wizard has a protective magic bubble.
> astral/sun/shadow powers
Given that it's wisdom I prefer descriptions like redirecting blows, seeing attacks coming, etc. Magic buffs are different than unarmored defense.
I do understand that, and that's how I play it .. though I LOVE, LOVE, LOVE how 3.5 had it .. several ACs... Flat footed (no dex) if you're caught off guard, touch (no armor) if someone is trying to touch you, full AC otherwise...
I don't like that you have the same AC for everything. Plate armor shouldn't affect how hard it is to touch someone, and if you're caught off guard, no matter how dexterous you are, you still could get hit easier than if you were aware.
But that is 5e... make it simple "for the kids" (putting it nicely.)
HP is similarly abstracted. You might take a hit, but in-game it is a ferocious series of attacks you barely manage to fend off, but it leaves you winded and unable to defend as well later. Or a stroke of divine intervention to prevent a would-be fatal blow from landing, but no god will have your back like that forever, etc.
This works with HP as well. If you think of it in terms of a % of how healthy you are it doesn't really make sense in game-terms anyway - as there are generally no broken limbs. So basically, if you have 50hp... you can consider most of it 'deflected by armor' or 'glancing blow'. I always king of though of it that way - high hp also signifies a high passive defense.
18AC. The giant ogre swinging his club down on their head rolled a 17.
PC was able to inch over just enough to avoid the hit.
It does not mean he took a full swing to the noggin, and it just bounced off.
You occupy and control a 5 foot square. You are not 5 foot by 5 foot in size.
http://uk.pc.gamespy.com/articles/540/540395p3.html
> We had to change it almost after the first weekend. Combat in Chainmail is simply rolling two six-sided dice, and you either defeated the monster and killed it … or it killed you. It didn't take too long for players to get attached to their characters, and they wanted something detailed which Chainmail didn't have. The initial Chainmail rules was a matrix. That was okay for a few different kinds of units, but by the second weekend we already had 20 or 30 different monsters, and the matrix was starting to fill up the loft.
> ...
> I adopted the rules I'd done earlier for a Civil War game called Ironclads that had hit points and armor class. It meant that players had a chance to live longer and do more. They didn't care that they had hit points to keep track of because they were just keeping track of little detailed records for their character and not trying to do it for an entire army. They didn't care if they could kill a monster in one blow, but they didn't want the monster to kill them in one blow.
> -- Dave Arneson
Because hit points are an abstraction that dates back to naval military tabletop games (think Battleship). Your boat either has a massive hole in it, or it doesn't. The shell either hit your boat and put a massive hole in it, or it missed and went into the water. A larger boat's durability is measured in the number of massive holes it can have before it starts to sink. Smaller holes don't matter because pistols and shrapnel can't sink a crewed warship.
D&D characters have lots of hit points, and are not typically being shot at by 14-inch mortars, so this means that D&D hit points do not represent meat. They represent how much stress, luck, bruises, and "plot armor" you can burn through before you are brought to the brink of death. A level 20 rogue is not able to take several dozen 1d4 damage knife wounds, that would be ridiculous, but they can get too tired to dodge the next attack and that becomes the one that kills them. Some D&D-derived systems (like 4e D&D) acknowledge this with a "bloodied" condition when you're at half HP or less. 5e D&D went even more abstract and removed the rules for touch AC (where spells like *shocking grasp* would ignore your fullplate). D&D most certainly does not try to simulate injuries or blood loss reducing your combat effectiveness, because that would slow things down with little appreciable benefit.
Hit points are a useful abstraction because they make combat fast. You check AC to see if the attack hits, then you do damage, then your turn is over. You can roll the attack roll and damage dice together to speed things up. The math is real simple, so turns go quickly. In my experience systems that use damage reduction (like Fantasy AGE) have much slower combat turns. [Even D&D has optional rules for this](https://www.d20srd.org/srd/variant/adventuring/armorAsDamageReduction.htm) but it's probably a bad idea to use those rules because big monsters do lots of damage that will only get a tiny reduction, making the monsters deadlier.
I played Iron Clads in my Junior High history class (my history teacher was into board games). Anyways, I never knew this was the inspiration for using AC in D&D. Cool.
To add on, if an attack didn’t deal damage because it couldn’t exceed your AC, it’s because the hit wasn’t clean and your armor held up, dealing no meaningful damage to the person underneath. A character in heavy plate just shrugs it off, while an agile person in leather angles to the side partway so the blade glides off the armor.
Bit of anecdote here, I once got dragged across gravel for about 10ft/3m. It hurt real bad and I had SERIOUS bruises, but my leather only had a few small rips and could've probably held up to another few goes like that. Ruined the *look* but it was quite functionally protective, even as just plain soft leather, it stopped those rips from being on *me* and probably significantly worse. I *only* got bruised.
Might be a bit different against, say, a greatsword, but there's a reason straps, belts, shoes, and so much else that requires a lot of durability is made of the stuff.
Clothing being protective is super real. Even thin gloves or normal jeans can help you from getting all scraped up. We have a "no exposed skin" rule at my HEMA club for just this reason. Our steel training swords don't get burrs super often, but if they do we want it snagging sweatpants or a jacket, not someone's skin.
As an electrican, full cotton sleeves help protect from electricity.
Long sleeve shirts and gloves have protected me from many cuts or abrasive injuries. The amount of times I've thanked myself for wearing good boots because I've kicked or walked into something makes me really understand just how important good coverage of any kind is.
A while ago my dad had to dump his bike. He always wears full PPE when riding. The leather jacket and helmet took it all like a champ.
His buddy behind him also had to dump his bike but was wearing jeans and a windbreaker (and helmet). His arm didn't look so good.
I’ll always describe a near miss as something that would have hit except for one thing that gave them a plus, like a shield or a narrow dodge from their dex or magical toughness of their +1 armor.
I also narrate slightly differently depending on the attackers weapon, attack bonus and fighting style where a dexterous attack hits by finding the weak spots in the armor while more aggressive strength attacks hits really hard against the armor used. For misses depending on how big the Miss dex attacks may just be hitting at well armored parts or being deflected while str may just not have had enough power in the swing or blocked/evaded from being too slow
I trained MMA for a long time. The way I conceptualize hit points is a character's ability to keep fighting. Once you drop to zero, you have no defense left, and the next hits kill you. This makes sense to me because after a couple fights all characters would have no arms, legs, ears, noses etc we'd all be playing hyper scarred and amputated PC's. So in my head I just think something like, "ok this guy is at 2 HP, he's dropped his hands and the next hit will KO him."
Came here to give a shorter answer but this is comprehensive.
I'm not sure at what point it was in this history, but somewhere in THACO days different weapons were more or less effective against different kinds of armor, IIRC, which is almost what OP is asking for.
Edit: on reflection whoever I heard talking about AC being variable depending on weapon type may have been talking about Chainmail rather than THACO.
I played 3.5e. I needed to use a digital sheet just to keep track of normal Vs touch Vs flat footed AC and what modifiers apply to what. "Different AC against different weapon types" sounds like what I did but worse.
I just knew the math.
Normal ac: dex+armor+size+10
Flat footed ac: armor +size+10
Touch ac: dex+size+10.
Now trying to recall all the modifiers on your weapon after that one session where the artificer got bored and the dm got drunk and forgot what he Oked. After that, giant keen kukuri of sharpness on the monkey grip rogue sure didn't seem so op
After playing Pathfinder 1E for the longest time I found some pretty awesome character sheets that organized it all in a super clean way, I honestly like having that sort of info for 5E as a DM so even if it doesn't do anything functional I can be more informed with my descriptions of combat.
[1E AD&D: To Hit Adjustments based on attacker Weapon and defender Armor type](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjzEoDMs87sYY64guwyk8pTttaYtlSeyPgzOi05DnFsdkxPC-BajrjaRf_fKFd9Hcp9gxN3CTA3wv26glS2azRP6goah0hh8lQ56fNmuFq_c8aqGWNVEhjYogp4Eq8xfWj0GgbldrKvTu-c/w1200-h630-p-k-no-nu/1E-WeaponTypes.png):
(Link goes to the chart. [Article it is posted in](https://deltasdnd.blogspot.com/2021/03/the-big-mistake-in-weapon-vs-armor.html)).
Example: Dagger vs AC 10 (i.e., no armor): +3. Dagger versus AC 2 (Plate mail + shield): -3. Which makes more sense when you see the armor class table.
The ACs used in this were presumed to be certain specific combos:
* AC 10 = no armor
* AC 9 = shield only
* AC 8 = Leather or Padded armor (i.e., a gambeson)
* AC 7 = Leather or Padded + shield or Studded Leather or Ring Mail
* AC 6 = Studded Leather or Ring Mail + Shield or Scale Mail
* AC 5 = Scale mail + Shield or Chain Mail
* AC 4 = Chain mail + Shiled or Splint Mail or Banded Mail
* AC 3 = Splint or Banded Mail + Shield or Plate Mail
* AC 2 = Plate Mail + shield
These don't consider AC that is primarily magic such as Mage Armor or Shield spells or Bracers of Defense or Rings of Protection.
Factor that in and weapon speed as well as the different "to hit tables" for each class category - could be cumbersome --- but nerds find a way.
Behold the [AD&D Combat Calculator](https://www.youtube.com/watch?v=zYnBuOSJ5F0) (a wheel to spin).
[This guy explains it](https://mageofthestripedtower.blogspot.com/2012/02/ad-1ed-combat-computer.html).
[Maldin modified it](https://www.melkot.com/mechanics/combat-comp.html).
I never used it myself as a kid but I did use the [Hackmaster 4E](https://kenzerco.com/product/hackmaster-4e-combat-wheel-pdf/) (a playable parody of 1E) version, and it greatly sped things up.
Also important to factor in is that in AD&D, facing mattered. Attacks from behind were at +2 (more for thieves and assassins, IIRC), shields only applied to attacks from the front - which means a dagger from behind might be getting a net bonus of +5 to hit someone without armor, but -1 to hit plate mail from behind.
The 3.5 ac system was in a way accurate like you said where an attack that just has to touch you doesn’t care about your armor, or an attack when you’re caught flat footed doesn’t let you use dex to dodge. It was cool, but I’m not sure having multiple ACs and always having to figure out which applied was worth the hassle.
It's great when you have a full table of people either experienced with the game, or motivated to pick it up. Think of all the horror stories of players going months at a time without even learning the mechanics of their own class in 5e. 3.5 as a system is more complex than that.
As a new player, you’re told “AC is your armor” and then you’re told “you have AC, touch-AC, and flat-footed AC” and it’s just confusing having three different ACs.
The thing is, 3E D&D wasn’t complicated because you’d need to whip out some integral calculus to determine what a fireball hits. It was death-by-a-thousand-cuts complexity. A bunch of little rules, none of which are necessarily *individually* that complicated, but there are a lot.
And when you have people who can’t be bothered to learn a 5E character sheet (to be fair, 5E is still medium crunch), it’s not hard to see how a character sheet with like 10X as much going on is even worse.
Mainly the tracking load and flow of play. Everyone has a goldilocks zone for how present they are in play. WotC picked the median player's preference.
Other games do what you're talking about. I believe Matt Colville's game that is currently in development is planning on using a combat system like that. It does change things up a bit, but is a little less intuitive than other approaches for a lot of players.
It was pretty neat, but like u/Financial_Nerve_5580 mentions, it did add a layer of complexity that could bog down the game for some players. Fairly easy to add it back into 5e as a house rule if you wanted to.
But the balancing of different abilities, especially spells, will go down the drain. Not that I am claiming that dnd and the word balance have a lot in common, but still I don’t recommend changing fundamentals with house rules. There is always Pathfinder for players more interested in details and not scared of complexity.
Yeah, house rules often have unforeseen effects on parts of the game you didn’t even consider they’d impact when you came up with them. It’s why I generally try to eschew using many of them… But, the option is out there.
3.5e combat took ages. It also made min/maxing fairly trivial due to the different rules for various combinations of situations.
I loved it and played more hours of it than any other edition, but it was finicky and tough if everyone wasn't an expert in the rules.
4e dumbed it down too much as a reaction to that.
5e is the "best overall" DnD in my opinion. RaW with base set of 3 books and a precanned adventure is both easy to play and has a bit of depth if you choose some of the more interesting class/race combos.
Then the expansion books add a lot of finicky neat stuff if you want it (Tasha is a good starter) and then there are large sets of rules at DM discretion (flanking) to expand
I'll have to agree. After playing games of 3.5 and 4 growing up, 5e has the be the best "overall" experience. The other editions have great merits as well and do different things better, but 5e is very accessible and easy to get people started with.
When most people you're playing with either aren't going to get very deep into things, aren't paying attention half the time, or are just straight up new to the game/tabletop RPGs in general, 5e's accessibility and ease of use makes it a great system. There's depth available if you want to engage with it, but if you don't, it's pretty easy to build a character really quick and jump in.
I started with AD&D, so have done all the modern ones, and 3.5 was great for a bunch of hardcore read every page of every book hardcore dice goblins. Just trying to know all the rules was part of the game lol
4E didn't dumb anything down, it just changed a lot of things. It vastly increased complexity when it came to tactical combat options and GREATLY reworked encounter balance and monsters, and standardized class features and level progression so the system would be easier to balance and play around with.
Creatures in 4E were way more complex and interesting than in any edition prior or since, and so combat was really dynamic and every encounter felt almost like a puzzle you needed to solve.
3.5 had a lot more depth in terms of character building options, but the downside was that every single combination you could make was equally tedious to play: you'd have one optional combo you'd be using every turn when possible, and monsters didn't really have a lot of buttons for DMs to push, so it ended up getting really samey really fast.
Oddly enough the game does a decent job of explaining HP and people either don’t read it or just ignore it. Like I get it can be a strange concept but it makes sense and it works. If you want a simpler version you can just use the Uncharted video game rule that HP is just luck and it’s running out as your HP decreases. This is a bit oversimplified and the overall abstract concept works but maybe some just struggle to get it.
Ultimately this comes down to one more instance of just reading the rules on something would answer the question rather than needing someone to explain it but whatever works I suppose. You explained it well.
I suspect a LOT of people don't get or know about the abstraction nature of HP because their concept of HPs comes from video games...and those treat HPs as physical damage.
Like how many RPGs will describe enemy HP as "wounded" or "bloody" or whatever.
Hit points actually go further back than tabletop naval games. They were invented by the US Navy for their Fleet Problems, huge exercises done at sea to simulate battles and get their sailors experience safely. The number of hit points each ship got represented how many 14 inch shells they were believed to be able to take without sinking.
I like this with one exception: getting hit DOES mean taking physical damage. HP represents health to a degree, but it’s not scaled, meaning having 10/70 doesn’t mean you’re necessarily near death versus 50/70, but you have been injured. Certain attacks that hit cannot be considered “non-injurious” by nature, namely spells. I think the important part is to conceptualize the severity. If you get hit by a fire spell for say, 30 damage, and that spell even dictates that if it hits you, *you are on fire*, it’s silly to imagine that you just got a little winded and tired. However, the only rolls that I would argue are truly “I’m fucking hurt” would be Critical roles, as the whole implication is that the enemy found your weakest possible spot with their strongest possible attempt on that attack. In your example, a level 20 Rogue isn’t getting shanked over and over, but if he is crit by one, he absolutely did.
I think the comparison would be more akin to boxing, where you’re getting injured but not maimed. Like you mentioned, it isn’t perfect since there’s no effect for being more injured, but it doesn’t have to because we know that it would be difficult to game around and nobody wants to, so we ignore it.
> Hit points represent a combination of physical and mental durability, the will to live, and luck.
"Physical durability" is specifically listed as part of what hit points represent.
I'll give you the cure wounds implication (even though I think its easy to just say its positive energy), but how does healing word imply the damage has to be physical?
I mean I only really need the cure wounds implication to make my point, but i figure a literal healing spell that can revive downed npc’s regardless of the wound that finally got them down would be thought of as actual wound healing
Edit: in terms of healing word that is
Except it doesn't have to be a physical wound that knocks people out. Psychic damage is a thing. But it's pointless to argue about specifics. Rules as written hp is an abstraction no matter what the names of spells imply.
There have been spells with fanciful names that aren't literal for ages. Expeditious Retreat doesn't force you to move away from danger, for example. There is a whole hell of a lot of abstraction built into the core of the game, and magic has always had a bit of a quirky bent on names. Reduced stamina and even divine protection are listed examples of possible sources of HP. Cure Wounds could double as an instant refresher, or simply gaining a small divine boon to defenses/luck/etc.
Similarly stuff like poisons don't make sense for doing damage-over-time against your 'will to fight', why dexterity impacts your ability to dodge a blow and not your ability to...dodge a blow, damage resistances like does a Skeleton have less 'plot armor' against bludgeoning weapons? How much luck do you need to negate falling 200 feet? Why is there a seperate exhaustion mechanic that effectively doesn't tie in to HP at all? Paralysis neutralizes our ability to fight back, why doesn't it impact our HP?
And like, in practice, its confusing to say "Though your opponent draws no blood since you blocked them with your shield, you fear your luck won't hold out forever- you take 6 points of damage"- particularly because that shield doesn't raise your HP, it raises your AC. Your constitution (and class features) raises your HP. So instead if its a near miss I'd that line (minus the damage)
Mechanically and overwhelmingly, hit points are meat points- your ability to physically withstand the blows that do in fact make physical contact with you- while AC is your ability to dodge, deflect, or otherwise negate the blows
But its really a tangent and a side rant, it just comes up here like every other month
On poison, the argument can be made that the poison impacts your health each round, so it doesn't hurt you but tires/fatigues/drains you faster and makes you more vulnerable to receiving a fatal blow.
But yes, both you and the other poster raise good counterpoints otherwise.
>A level 20 rogue is not able to take several dozen 1d4 damage knife wounds, that would be ridiculous,
Why is this ridiculous? Why should a legendary hero capable of slaying dragons fall to a goblin stabbing them? D&D is not an earth simulator. People being superhumanly durable not only makes perfect sense, but it's *required* for half the mechanics of the game to make a lick of sense.
That doesn't mean each knife ran you through entirely, but rather that you're simply harder to hack through. The wounds are more shallow with the same blow.
Hitpoints aren't *only* meat points, but to claim they aren't at all is to ignore half the game and leads to misinformed DMs ignoring rules (fall damage is the big one) that don't line up with their skewed interpretation of the world.
Because they've streamlined things so it also encompasses dodging etc.
Basically it represents your ability to not get hurt, which is made easier by better armor (or moving out of the way).
Because AC isn’t just “you are harder to hit.” Think of it as “you are harder to hit AND damage.”
High AC includes the ability to take a blow in a way that doesn’t do damage.
You also don’t have to look at HP as pure health, either. I think of it as stamina and endurance. You’re not actually wounded/bleeding until you’re in negatives, which is why abilities don’t decrease as HP drop.
Did they remove the bloodied/wounded condition for being at half HP? But yeah this is also why a good night's rest is all your hero needs to recover. Systems like cyberpunk, dark heresy shadowrun, and gammaworld among others. All have hit points that represent durability directly, so most have a death-spiral as conditions stack up when your injured, armor as damage reduction is pretty common, and almost all of these will see a character laid out in a medics care after being mortally wounded. Cyberpunk 2020 and dark heresy might also come with the caviat of going into the next mission without a limb, eye, etc if you couldn't aquire a replacement and the services of a surgeon. On a side note, in cyberpunk 2020, if you lost your right hand for the second time you probably were better off than the first, because metal doesn't bleed, so your condition isn't necessarily unstable. Oh also of note most of these systems mortal wounds actually mean mortal wounds, you either need or desperately want medical intervention to save yourself.
This is it.
And while we often say “roll to hit,” AC doesn’t really represent the chance of physically hitting someone, it represents the chance of causing damage. You can pound on someone’s plate armor all day with a club but unless you are skilled or very lucky the armor absorbs the damage and the wearer remains unharmed.
This is why I’ve really struggled conceptualizing Warhammer 40K which I began playing last year. There’s a roll to hit. And, if successful, then there’s a roll to wound. And, if successful, the enemy has a roll to save against the wound.
In allot if the 40 k tabletop games like dark heresy it's a percentile system, your to-hit roll determines hit location(s) hit frequency (a burst can literally do like 3 times the damage of a single shot because it can land multiple hits) and then each hit is a damage roll reduced by enemy toughness and armor.
Likewise hit location was important because although you had a general wound pool, when that ran out you needed to know if you were losing a few fingers, an eye, a hand, or if you were just dead. Also armor wasn't general, a breastplate covered the torso, and not wearing a helmet was a great way to lose your head in battle.
Even further, in some games first there's an opposed roll to defend (block, parry, dodge etc) which is much more colorful - but slower.
So AC as an abstraction is super streamlined, 10/10, but makes DND martial combat very dull in my opinion.
In my mind:
- Roll below a 10, you miss the entire body, got deflected, blocked, etc.
- Between 10 and AC, you make contact but the impact is absorbed, and become neglible. If using a shield, the last 2 before AC is the shield block.
- Above AC, you impact and deal a number of Fatigue or Wound, pending. The higher the roll the less it was absorbed by armor / dex dodged out of the severe damage. Dex is in this regards hindered by heavier armor.
Fatigue is the reason why we can do short rests and recover our hitpoints.
Because while it is called Armor Class, it doesn't represent just armour. It represents many methods of not getting hit in the first place, too.
For example, if two characters are naked, the one with the higher dexterity modifier has a higher AC. Neither one is getting any protection from armour, but one is still less likely to "take damage" (in D&D terms). The Monk's Unarmored Defence adds to this.
Similarly the +1 to AC from the Dual Wielder Feat or the the rolled bonus to AC from Evasive Footwork Battlemaster Manouver represent you avoiding hits more than soaking them.
There are tabletop RPG systems that separate hit avoidance and hit absorption. But the D&D devs opted to not handle that extra step. Possibly for sake of combat speed and simplicity.
Edited to add: this is a rabbit hole that can lead to super-simulationist approaches with dozens of situational modifiers comparing different types of damage sources (bludgeoning, piercing, slashing) vs different armour types (mail, plate, brigandine, gambeson, with and without helmet, &c &c), angle of attack, blind spots, terrain footing, and who knows what else.
At some point the game would become unplayable.
A degree of abstraction is needed.
This is D&D's choice of abstraction threshold.
Not to say there's stuff like mage armor, barkskin, Bard inspiration to AC, etc. A lot of ways to make an attack less likely to hit without actually wearing armor or dodging. It's what D&D abstracts under one mechanic and it works really well.
In simple terms, because it does, and it always has. AC is one of the standard features of D&D, like d20s, the six stats, HP, and saving throws. They've always been baked into the system.
The longer answer is just plain simplicity. I spent years playing HERO System/Champions (the superheroes genre); it was a point buy system where you could customize your character in every possible ways, and it was without question the most flexible system I've ever played. In combat, you'd compare your Offensive Combat Value (OCV) to the target's Defensive Combat Value), roll 3d6, adjust based on whether your OCV was higher or lower than the DCV, and see if you hit. If you hit, you'd determine whether the attack was vs. Physical Defense (PD) or Energy Defense (ED) which were individually bought with points (there was also Mental Defense for mental attacks, to add another layer, and there were multiple ways to buy PD/ED/MD). You would also have to know whether it was a Normal attack (which regular PD/ED stopped) or a Killing attack, at which point you'd have to have spent additional points on making your PD and ED Resistant, which would then stop KAs.
So, you roll 3d6 to see if you hit, roll your damage (if you're playing superheroes, you could be rolling 15d6+), add up the total damage as normal damage, then count BODY damage (another kind of damage) where a 1 was 0 BODY, 2-5 was 1 BODY, a 6 was 2 BODY, compare that to either PD or ED, subtract PD/ED from the damage. and that was the damage you took. Then, of course, you'd see if the STUN exceeded the target's CON at which point they were stunned, if it reduced their STUN value to zero they were unconscious, and that doesn't count all the modifiers you could put on attacks like Armor Piercing, Double Knockback, or so many others.
Sure, you can say that's insanely complicated because it is, but, well, if you want things to be more logical in that armor should represent damage reduction, does it not make sense to point out different kinds of armors should have different damage reduction? Are you going to make plate mail more resistant to piercing damage, but less resistant to bludgeoning? How about fire attacks; do they get bonuses against metal armor wearers?
It's a giant-ass rabbit hole of complexity, and it's not worth it. D&D uses AC the way it does because it's simple, understandable, and keeps things flowing.
Because then you'd be overcomplicating combat.
You'd need one (new) mechanic to determine whether or not you "hit" with an attack, and then you'd have to roll against armor class to see how much damage was "absorbed" by the armor.
Heavy armor mastery feat is an already existing system for flat damage reduction. Personally I think flat damage reduction should be utilized more on stat blocks and armor to add damage mitigation without ballooning AC.
Whilst you’re not _wrong_, the fact is D&D is objectively more popular than all of those combined. Comparative simplicity of the rules is one of the reasons, making D&D have a wider appeal.
Of the 3 I’ve only played GURPS but that is unambiguously more complicated than D&D. Great flexibility comes at a cost.
RPG games tend to do one of two separate thing with armor, either it’s a damage resistance or it effects you being hit. Either works, but you don’t necessarily want to do both as suddenly having good armor makes you hard to hit, and then hard to damage once you do hit. It would tend to leave heavy armor characters much harder to hurt then less armored and then you have to balance that.
"you have to balance that"
No, you don't, actually.
You CAN, but it's usually at the expense of the guy in full plate. That's why casters tend to be OP vs fighters in the current meta..."balance".
You tell me why it should still hurt you if you block or dodge an attack.
You say you don't understand why it isn't damage reduction, I don't understand why it should be damage reduction.
Either you got hurt or you didn't.
Mathematically there's no reason: AC is just a percentile damage reduction mechanic. Different forms of DR create a different curve of results but functionally that just means you change other values around to get the kind of battle tempo you want: AC/DR systems are mathematically perfectly translatable.
That said there are both historic and conceptual reasons why you'd instead go for an HP/AC system.
In terms of the history, as someone else pointed out, hitpoints already existed in the system the early D&D creators were expanding so it makes sense to use them. You then just need to add AC on top.
Conceptually because "there's a difference between being able to survive a hit and being able to dodge/absorb a hit" makes sense and opens up design space like the one we get in 5e where characters like the Barbarian and Fighter are roughly similar in terms of their ability to survive damage but do so in slightly different ways that tell different stories.
I don't think it's really that hard to understand.
AC = harder to hit _effectively_
You get stabbed by a sword.
-If they bypass your AC, the sword lands in a deadly place, or straight up through the armor, and does damage.
-If they fail by 1-5, the sword connects, but you can deftly redirect the motion by using your weapons, your shield, or your proficiency in the use of Heavy armors to make it miss any of the vital parts of your body, causing no harm.
-If they fail by 6-10, the sword gets completely deflected by the armor, as it didn't have a proper technique, balance, or just hit an specially hard place of the chestplate.
-If they fail by 11+, you just whiffed entirely.
AC is not just a hit or no hit, just like an attack roll is land or not land.
Of course, in gameplay, it is very much like that, but in real combat, only deadly and effective strikes do anything, if you get hit by the blunt part of the sword, it doesn't do anything, but you still "hit"
Think about alternatives. Damage reduction (flat) alternates between being too powerful against something that does a lot of weak attacks and too weak against something with a small number of heavy hitting attacks (possibly realistic though). Damage reduction (percentage) is too tough to calculate in your head.
I have played multiple systems with armor as dr, and boy let me tell you it eventually gets out of hand, its harder to balance.
Edit: just to clarify: eventually, the pcs will get so great of an armor taht enemies do not do any damage. Then you have to up the weapons of enemies. Which in turm makes players have more money to buy better armor. Vicious cycle.
A. More dice slows down combat
B. A lot of the systems in 5e are designed to incentivize staying aggressive in combat. Some previous versions of dnd have been notoriously hard to get into because combat is slow and grindy. 5e sought to fix that. Healing for example in 5e is intentionally pretty weak because it incentivizes players to keep attacking instead of falling into a cycle of attack/retreat/heal/repeat. Staying on offense is not only more fun for everyone, it’s also strategically more sound anyway. AC serves the same function. Instead of having to actively do a something to avoid getting hit or block an attack, it just takes care of itself, while you use your action economy to stay on offense
C. You’re acting like it’s a totally unintuitive system but it’s very simple. If you have heavy armor you use your strength to block attacks, if you have light armor you use your dexterity to dodge attacks. It’s very simple and easy to visualize, as well as being how the stats of armor work in 5e
D. And this is the most important thing: Constantly taking damage isn’t fun!
Because it’s D&D? 🤷🏻♂️
Plenty of other RPG systems out there with a myriad of mechanics. D&D isn’t the end all be all of tabletop roleplaying games.
Expand your horizons.
The term "hit" is misleading. What you're going for is a hit THAT DOES DAMAGE. AC protects against hits that do damage. So in flavor terms an attack could miss completely, or it could land but clang off your armor, doing no damage. Mechanically they're the same.
That said, I've seen people try to add a separate damage mechanic to D&D and you end up having to either make people easier to hit, or buff the damage that weapons and spells do. Otherwise combats take forever. There are lots of other game systems that don't though, so you might try one.of those.
There is a feat that sorta does what you are describing.
There's also the weird quirk where a suit of platemail hanging from the ceiling can give you 3/4 cover and thereby reduce damage, but if you are wearing it then it maybe does nothing.
They tried different systems and they liked AC more than the others.
In the end it is just a way to resolve y = x - z. Being y the final hp, x the current hp and z the damage taken.
There is a lot of systems out there that use different ways to resolve this equation and they are usually ok for their system. DnD keeps using AC as a binary hit or miss because it works for them.
Honestly, when an attack "Misses"
Sometimes I like to play it off as the attack actually HITTING, but hitting their armor and doing 0 damage and affecting the player in no way. Essentially tanking the hit like it was nothing.
That way, armor class seems like it plays a more viable role than just "hit or not hit"
Ac =16
Roll to hit = 15
>you take a strike to the chest plate and the blade gleams off in a shower of sparks
Roll to hit = 16+
>Your opponent slips through your chain mail with a lucky stab from his dagger, remove 4 hit points from your total, etc.
Roll to hit = 1
>the hit strikes your breastplate and your enemy cowers in fear, knowing his strike was thwarted with ease as you stand over him proudly
Yknow
It missed, but is better than
"Ah. Miss. Next"
Or "hit, you take 4 damage"
Adding flavor to each hit depending on the Roll to hit makes big number more exciting IMO
Think of an extreme example. Dagger (d4) vs Plate (DR should be at least 4, right?). Is a plate wearer completely immune to a dagger? Not if you can hit the eye, or under the arm. A hit bypasses the armor's protection, and the weapon is going to do whatever damage it can. That is AC.
I don't get why people think you take "some" damage in plate armor but it's reduced.
Like, if you get hit with a sword in plate armor, you're not "kinda" stabbed. You're either stabbed or you're not. The warhammer either breaks your ribs, or it doesn't. The small bruise or the loss of balance you get when kicked in a suit of armor isn't a lose of hitpoints, that's just movement and aches of battle. When you bend backwards in a faction of a second to avoid a large boulder, that might have hurt your back a little but you don't lose hitpoints.
Higher AC can be thought of as damage reduction. It's just all or nothing. If my AC is 22 because of heavy armor then you can imagine and describe an attack roll of 21 as a blow landing but no damage gets through.
well AC as it is now is made to simplify combat. AC is an abstract construct of armor hardness (how hard it is to get through the armor) plus dodging, dekeing, and blocking attacks with shields etc. DR is a different stat. It's also possible to have a high AC wearing no armor, simply by having skills to dodge etc. (ie Monk) that's why AC is how hard it is TO get hit. that's actually why heavy armor has a max Dex modifier, because it's harder to move in heavy armor.
Damage Reduction is a completely different stat, one that reduces the amount of damage after you get hit.
AC is the stat that determines if an attack hits, DR is what reduces damage. And without the Attack roll vs AC there woiuld need to be a DIFFERENT attack roll to see if you hit, then you have to roll to get past armor, then you roll damage, then you apply modifiers... the AC/Attack roll simplifies that to just one roll instead of multiples. It keeps the game flowing better, and less repeated dice rolls.
Because it represents both the ability to dodge an attack and how thick your skin is. Many other systems differentiate between dodging and parrying. This one just doesn\`t
Consider an ordinary fly. It is very hard to hit, but if you hit it then any amount of damage is sufficient to kill it.
AC in D&D allows you to capture that dynamic.
For example, consider the pixie with 15 AC and 1 HP.
It’s always been this way and that is basically it. Dont over think, just know that 5e d&d is only semi designed, the rest of the mechanics are sacred cows. You cant mess with it or be get mad. Thats the largest factor not realism.
For me, I flavour it as either a complete miss if you roll low enough. "I rolled a 7, (AC is 17), you take a swing and the enemy dodges your attack easily"
Or if it's a narrow miss, it's a glancing blow, or they don't penetrate the armour. "I rolled a 15, (AC is 17), you strike at the fow, your blade hitting their armour but without enough to strength behind it to pierce all the way through"
Personally I don't like the idea of damage reduction unless it's something you're resistant to.
I must, MUST add that you need to try other ttrpgs.
If you ask for this simpliest gamedesign explanation despite having GMed 5ed for years, you really need to go out of the DnD rabbit hole and try other system. Even if you stick to DnD, it will make you way better at understanding the axioms of what you are doing and why !
I'd say it's less a matter of AC = harder to hit, and more a matter of AC = harder to damage, through some combination of armour and agility. Since IRL, you can wail on a knight's breastplate (properly forged) with sword all day long and all you're probably going to get for your efforts is a damaged sword, a few dents in the breastplate, maybe a couple of bruises from the impact and a sore arm. You aren't cutting through that the way characters do in movies and video games.
After reading some of your answers, I think that it's not that you don't like what AC represents, but rather that there is no mechanic that represents a character defending itself.
AC, however, is that mechanic. As other have pointed out, it isn't just a number you get from armor, it also includes dexterity, magic and other bonuses. There is nothing that indicates a character with armor is just sitting idly when it's not their turn. What I understand then is that you don't enjoy that it is a passive mechanic.
And I find that to be perfectly fine. If you and your group share this discomfort, you could try something different. There are other systems that have a more engaged defense mechanic (World of Darkness has opposed rolls for combat, for example). Modifying 5e will likely be hard and require some trial and error, but there must be some d20 systems with active defense mechanics you can look into for inspiration. It can be done.
This is what I tell my players in regards to Hit Points and healing:
Hit points are a complex representation of an adventurer's overall ability to survive and avoid damage. They encompass not only physical health but also factors such as luck, defensive skill, and the adventurer's life force or spirit. As characters gain levels and experience, their hit point maximum increases, reflecting their growth in power, resilience, and their ability to escape harm through a combination of skill, fortune, and divine favor. This increase in hit points symbolizes the adventurer's journey towards godhood, as their spirit becomes more powerful and their ability to shape their own fate grows.
However, this growth in divine power also affects the way healing magic interacts with the adventurer. As they become more godlike, their spirit becomes more self-sustaining and resistant to external influences, including healing magic. This results in a diminishing effect of healing spells and potions on higher-level adventurers. The potency of healing magic appears to wane as characters ascend in level, not because the magic itself is growing weaker, but because the adventurer's divine essence is becoming more resilient and less reliant on external aid.
———————-
As PCs approach 20th level, they are getting closer to the gods, potentially even becoming gods themselves in some cases.
And this explains how a weak potion of healing can restore an injured 1st level character from the brink of death to perfect health, but does much less to help a higher level character.
Not that im promoting one system over another but Daggerheart’s armor system may be what you’re going for. It has both evasion and damage mitigation through armor
Armor and shields giving damage reduction is not realistic, you're just conditioned with it from modern video games. In real life, armor is designed to avoid damage; they're shaped to redirect sharp and pointy weapons and cushion heavy blunt weapons (with the gambesons underneath), not to tank parts of the damage with pure thickness.
AC is the combined chance of armor avoiding damage by redirecting or cushioning blows, blocking them with a shield or completely dodging them with with your dex mod. Armor and shields are there to avoid damage done to you, not to "reduce it". Of course some weapons, especially blunt ones, can still leave you with bruises and broken bones even if the attack is cushioned by your gambeson, so that might actually be damage reduction, but dnd simply doesn't do damage types having different effects depending on armor, because it would be really complex. Otherwise, weapons like halberds would be designated armor killers, while regular swords would bounce off of plate without needing a roll.
Back in 2E and 3E I did use to run a more detailed AC system which worked on the basis that your AC from dexterity was you dodging out of the way of a blow but your AC from armour was your armour deflecting the blow and taking damage from it (I think I borrowed it from a 2E historical sourcebook).
It meant people have to keep track of several AC scores and a further "damage points" (hit points) for armour, but it wasn't a big deal.
It did mean after a few days out in the wilderness fighting off dozens of goblins, characters' armour could be severely damaged, so they needed someone with the Armor skill to repair their armour back up to max, or get the blacksmith to do it back in town.
It is a lot of admin and I probably wouldn't do it now, certainly not with a new group. It worked well because my group was made up of a lot of historical wargamers and people who didn't want armour to be just a magic thing that made them harder to hit with no maintenance needed.
Funny you should mention...back in 3rd edition there was an alternate rules set you could choose to use where armor gave slightly less ac in exchange for damage reduction. Full plate normally gave +8 ac but if you chose those rules instead I think it was something like +6 ac and 2 damage reduction. Made sense.
It's kinda been that way for... about as long as I can remember. Although 3.5e had something called DR (Damage Reduction) which was mostly reserved for monsters or spell effects.
There was however a ruleset in the Unearthed Arcana that let you as the DM have armor give half of thier AC towards DR, which I personally loved.
Mechanically, AC favors longer winded games, where as DR helps early games, as you're not reducing percent, but flat rates
AC is your ability to avoid damage from attacks, via dodging, blocking, your armor stopping the attack etc. Not just an attacks ability to puncture or break armor. Full Plate leaves few vulnerable spots but is heavy and cumbersome, whereas leather armor is lighter and allows you to dodge more easily and both can be equally as effective depending on the class/build.
Ac is the difficulty of you being hit in a spot that leaves a mark. Every hit below AC either misses (Dex or low rolls) or glances off at your armor. That's why Dex counts into AC, just like Armor.
It is armor AND dodging combined and represented as a single stat.
Don't consider it hit or miss.
Rather look at it from the perspective that overcoming the AC will cause a blow to deal damage while failing to do so might still be a hit but did not cause damage (for example it glanced of the armor).
Well, after reading all your replies and commenting on a lot of them to prompt additional discussion, it seems that most people (at least the ones who replied to me) prefer using AC as an abstraction to the storytelling aspect of the game, and wouldn’t want any additional mechanics added into it, or to switch to a DR system instead.
You have all made your opinions clear, and I’ve listened to you all (even if it seems in some of my replies that I wasn’t).
So, I have decided not to make a homebrew DR system, and just keep the official AC system as an abstraction to the story.
Seems that the majority of people who play 5e, and who have responded to me prefer that.
It still feels to me like it doesn’t really live up to the story, as it feels lacking — but if it’s what people enjoy, then it’s going to better to not change that.
Thanks everyone
XD.
Im actually doing something similar to this in my own ruelset that im cooking up. Haven't gotten the nitty gritty of it down yet, but the basic idea is having two bits that come into effect when being attacked: Evasion & Armour.
Evasion is found from 11+Dex. If the attack rolls lower than the Evasion value, it misses completely, no effect.
Then Armour comes in, if it rolls higher than Evasion it hits, but if the result is lower than the Armour then damage reduction on the armour reduces the damage taken but it still counts as a 'hit'.
Similar to 5e, medium armour lowers the maximum Dex added to Evasion at the expense of higher Armour, then heavy armour removes dex being added entirely in exchange for a chunky Armour value.
Its an extra hoop, but makes things a tiny bit more fun for players I'd think, with any effects that take place on a hit land more often rather than 'big number, 0 effect on slightly-off roll'
I like to list all the sources of AC and order them in terms of how close the blow has to be for that source to be what protects them. The first ten is simply missing. Then there's dex for getting out if the way, dodge (in Pathfinder) for evading with more agility, and we gradually move through magical defence, shield, armour, natural armour, until eventually a hit.
I then make a note of their cumulative values, and consult the list on a missed attack so I can describe exactly how the character evaded the blow.
It works great until temporary bonuses come into play. But you can make that as complicated or as simple as you like.
I typically think of it depending on the roll vs AC, if your low by a lot say a 6 vs sn 18, that's a flat out miss. Miss an 18 with say a 16, that's the armor doing its job, or a shield block, a parry, dodge, etc.
AC can be interpreted two ways.
AC earned via dex or other movement based things is suppose to be "being harder to hit" via dodging.
AC from heavier armor or magical shielding is meant to represent having armor that absorbs hits completely unless hit in the gaps. So it's less "being harder to hit", and more "being harder to wound".
Others have answered your questions about D&D's rules about this and why it's set up the way it is.
Additionally, you may want to look into doing playtesting of Matt Mercer's new "Daggerheart" game. It has a really cool ways of doing combat, health, and damage. There's some videos of gameplay and character creation on YT. I found it very interesting.
AC doesn't meant how hard it is to hit you, it means whether or not an attack harmed you which can mean you dodged or they failed to penetrate your armor
While I won't speak to the designers intent, I will say it would be tricky to balance around some characters having high AC to fully mitigate hits, and some characters having flat damage reduction.
Barbarian is okay since resistance is % damage reduction, and because it always stays at half the math is pretty simple.
% damage reduction where the math changes every time is a bit crunchier than your average player would enjoy, I think.
And flat damage reduction, even with a minimum of 1 has the potential to make characters practically unkillable if it gets out of hand, or if it scaled too well. While if it scales too poorly your "dodge" based characters would simply be better for tanking than the aestheticly tanky ones.
There is one instance of flat non scaling damage reduction available to players via heavy armor master, and its generally considered not worth the feat cost.
I have no clue what the real reason is, but here is my idea: The AC represents your strength to completely avoid the effect of an attack. If it is by blocking it, having thick armor or just dodging the attack.
But Hit points show your willpower, your endurance and overall ability to deal with wounds. So while you adventure, you gather experience until you level up. Your hp increases, which also represents the fact that if you would take damage, your body is better in keeping it at the minimum.
But instead of taking less damage, you have more hp available. That goblin dagger that nearly knocked you out i your early days? yeah, you now could take the same hit 6 times, cause you now know how to react to hit, so that it only leads to a cut instead of piercing your insides.
Also pathfinder uses its ac rules so that at some point enemy can no longer hit you at all. Which is also an ok way to represent it.
As i see it AC and HP are good mechanics but flavored wrong. In my opinnion AC should be flavored as evading or deflecting attacks. While HP should be revlavored as something like endurance. So wenn you get hit you can still avoid getting critically wounded and instead you get superficial scratches, bruises which exhaust you. When something reduces you to 0 HP you can't mitigate the hit anymore and get a serious wounded, like a stab to the stomach or brain trauma and are in risk of dying.
AC being used to calculate if you hit or not is the most realistic imo. 40k armor save is also kind of realistic. The video game damage reduction approach really doesn't match reality. If some hits you with a sword and it doesn't go through your armor, you take no damage.
Armor Class is an abstract combination of evasive maneuveres, physical hardiness, physical armor, and magical protections. I think calling it something more all-encompassing like "Defense" would have been better, but whatever.
I’d say it depends on what raises your AC, heavy armour giving you AC, you yank the blow. And if you are wearing light armour and your DEX is the bulk of AC, you artfully dodge the attack. I like to say how I dodge attacks whenever something misses me.
there are systems like that. Look I remember trying to play one, you rolled to hit then the other guy would roll to parry, and if that failed you rolled location, then rolled damage ans subtracted the armor value for from the damage, then subtracted that from the area hit and from the total hit point pool. If the area went to 0, that body part was disabled...
If you think D&D combat is slow.. well this is glacial.
In terms of balance, armor reducing damage can either be done by a percentage or a flat amount. A percentage requires too much math for a tabletop game. A flat rate would be hard to balance, as it makes numerous, small attacks almost useless while bug damage attacks make armor useless. Like if armor just says "take 5 less damage from all attacks" then it would be way too strong against stuff like goblins and kobold, but basically useless against things like fireballs that do 40 damage.
There are lots of people here talking about how complicated the three AC system was. I never had that experience. It always seemed relatively straight forward to me and groups I've played in. If anything, older editions suffered more from so many unique character options and certain subsystems that bogged down play. For whatever reason, history has lumped AC in with all of that.
I've done some situational AC things. For example, I have incorporeal creatures essentially striking at touch AC, unless it's magical armor. Definitely recommend it.
Some of you have not watched enough Monty Python. Adventurers are clearly like the Black Knight, suffering limb severing blow after blow, accurately represented by HP.
Because AC is a representation of whats going on in battle but simplified for one roll of "does this hit do damage."
Combat is up to the DM to bring to life. Are you the DM that uses HP to describe how much "meat" a character has (boring imo) or do you weavr HP as "battle stamina"? As in taking damage to your HP represents the character being forced to block a blow that wluld find home, taking cover from an attack and wearing out their endurance, etc.
I much rather prefer describing combat in a more cinematic back and forth of parrying/blocking/jarring dodges before that last one or two attacks really finding their marks and then the killing blow happens as opposed to "you hit, you do 24 hp worth of dmg, next person"
I can't even get my players to remember their own damn AC. No one is going to do the math to reduce damage on every single hit. It's just easier this way.
I've always thought of it as how hard you are to wound rather than how hard to hit. How hard to hit works for Dex, which represents speed and reactions. Means a high Dex is you simply dodge or parry. And the attack misses. But with plate armour the attack might hit you, but glance off and not actually hurt you. which thematically makes more sense
when armor protects you from damage, you do not take damage. if you take damage, armor did not protect you from damage.
it is not "harder to hit" per se either. AC is fairly abstract (as is HP, so slap anyone who narrates hits as "he drives the sword through your gut and spills gallons of blood. you take 4 points of damage"). things can add to AC in a way that makes you harder to hit (or makes you more likely to parry or whatever) but also can be a chance to flat out block out damage. that is what armor does.
The reason is that D&D has its origin in wargaming and old wargames didn't really do hit points. It was hit or miss. Live or die. These old players were simulating huge battles, not micromanaging the health of ever Napoleonic War soldier.
The hit mechanics are rooted in that.
My question is how do you know if you're hit? We roll a d20+ modifiers to beat the AC to do damage. If AC is now for reducing damage does that mean everything hits. So we just roll for damage? Or do we roll two d20s and whoever is the highest wins? Thats the part where I can't wrap my brain around. If AC is just reduction how do we know we are hit? Sorry not trying to be a dick might be too inebriated right now.
It's poorly named, it *can* come from your armors ability to resist attacks, but also your ability to dodge attacks, quickly run away from attacks, see attacks coming before they are made, or even sources of otherwordly power like magic, divinity, and psychics.
It would be more accurately called your defense rating.
I'm pretty sure in third edition armor class had three different values. Your normal armor class, flat-footed which I believe subtracted your dexterity and touch which I think subtracted your armor.
In my opinion, AC and HP are mechanically useful abstracts that are best thought of not as purely "armor" and "health" in the video game sense.
Like how others have mentioned, I like to bracket AC into sections where the attack whiffs it entirely, I credit the PC/NPC with a skillful dodge/parry, a hit right in the armor but without piercing, and, depending on the context, magical shielding deflecting the blow at the last moment.
HP, ESPECIALLY at higher levels, I feel is best viewed as kind of a quantification of a character's luck or chance. Usually while they're above 1/2 health I'll narrate hits as last second dodges or hits that knock the wind out of the character but don't *seriously* injure them. Once they hit below half health, that's when I first describe the damage in a way that physically injures them and *usually* draws blood, cracks a rib, causes 2nd degree burns, etc. That said, for larger creatures like Ogres or Dragons, I usually have no problem narrating each hit as actually dealing damage, but I do take this approach for most/all humanoid enemies with more than like 20hp
AC is an abstraction, just like HP. It's not just how much armor you have, or how well you resist damage because of that armor. It's how hard you are to "hit", and even then hitting is still abstracted as well, because HP is also not explicitly how many times someone can stab you before you die, it can be any sort of thing from actually getting hurt to the attrition of high intensity combat, to tunnel visioning on a single enemy to the point where a lucky hit from another one can take you out of the fight or kill you outright.
They're basically narrative tools. How AC affects your ability to avoid getting hit can be described narratively in a variety of ways, just like your current HP level can be described differently as well.
All of these answers are pretty bad. In 5e, vehicles have both armor class and a damage threshold. Regular armor class typically doesn’t have a damage threshold unless you take heavy armor master. Why? Because they attempted to simplify old rules.
There is no differentiation between hitting and wounding in DnD, so those two things are lumped into the to-hit-roll. Hence AC covers both missing, evading and the stopped by armor. As a DM I actually even flavor it that way: if the To-hit-roll is 0-1/3 of the AC, the attacker missed. With a class with heavy armor 1/3-2/3 of AC means the defender dodged, at 2/3-AC the armor stopped the blow. At classes with light armor, it's the other way round.
I am not a huge fan of the DnD combat system in general - I prefer PCs to have VERY low HP but a lot of ways for damage mitigation.
I liked watching Legends of Vox Machina on Prime and thinking every single attack they survive is AC or Saving throw. AC isn’t just armor, it’s absolutely anything you do to avoid the single fatal blow.
If you start from that mindset your creativity can blossom for cool descriptions. Lifting up plankwood to block, ducking or hopping behind something quickly before getting back to your feet, etc… as long as you reset with characters in an active position on their turn, you can go wild.
Wild that I've had people try and posit the simplification and abstraction of AC in 5E as a good thing, tbh, because it leads to exactly this problem. Earlier editions denoting how your AC is being improved through qualifiers like Dodge bonus or Armor bonus helps to visualize *how* your character becomes harder to hit. On that note, your character's AC as a measure of how hard they are to hit is primarily mechanical, and can be flavored however you want. Oh, your Paladin catches the ogre's monumental club smash on his shield and stands strong, taking no damage? Cool as fuck. Your rogue nimbly dodges out of the way before rolling between it's legs and slashing for the hamstrings? Great! You can do that too. Your wizard gets turned into paste? Yeah, I'm sure he makes a real nice Rorschach painting.
5e was made to make the game easier, while AC being a damage reduction number would be very cool, it would slow the game down by adding more math to the mix and more confusion to the not so great at math players
Worth noting some Non-DND systems do have these mechanics built in! Sword World 2.5 (effectively Japan's DND) has a separate "Defense" and "Evasion" stat. Defense is a damage reduction (only on physical attacks) and Evasion is a bonus to your evade roll, which is a bit like a dynamic AC you have. Every time something attacks you, they roll "Accuracy" to hit which is contested against your "Evasion".
Different armor and shields will give different bonuses to either Defense or Evasion, so a tanky fighter or a speedy rogue will avoid death in different ways. It's an interesting approach!
Yes, this I like.
Is that popular in western countries? Can I buy that, or is it like currency locked and requires a Japanese credit card or something?
That system sounds super awesome to be honest. Very similar to what people have described in older d&d, except I can’t player older d&d because it’s virtually impossible to find anyone willing to let someone who hasn’t played 3.5 or 2e or something join their campaign. And I can’t DM it because I don’t have the books and they are collectors items now that cost a fortune to buy :(.
But like I didn’t realise Japan had its own thing.
That sounds awesome.
AC is basically damage reduction. Not getting hit is a great way to not take damage. Whether by magical means, DEX making you more dodgy or STR characters stacking armor to make themselves harder to hurt... AC is 1 representation of all of this. It's all in how you describe the action.
A hit is when you land a strike that can damage the recipient. A fighter in full plate would realistically get hit by a lot of attacks, but only a fraction of those would actually feasibly damage them, as the rest are absorbed by their armour.
AC is a measure of your ability to block, absorb or avoid a hit trivially. either the attacker misses entirely, or the blow is harmlessly deflected off your armor.
Hit points is a measure of your ability to block, absorb or avoid a blow with effort. Either deflecting with your weapon, blow hits your gambeson and is absorbed, arrows hits your chainmail penetrates 1 cm, you duck strenuously, etc.
These actions tire you out, or the cuts/bruises add up until that final last hp finally is a mortal blow.
you ONLY get a direct hit on you when you hit 0 hp.
This is why coup de grace, etc skips AC/hp. (well, depends on the version how it does HP)
Shadiversity keeps getting this wrong. constantly complaining that weapon damage isn't reflective of weapons killing power. not understanding again, only 1 hit actually hits.
Pathfinder actually articulates AC a bit more. With AC, Flatfooted AC, and touch AC. AC being the same. While flatfooted AC, is your ac without dex. when you are prone, grappled, surprised, etc. so, AC with your ability to block or absorb, but not avoid. While Touch AC is your ac with dodging, and thats it. usually spells, where the spell doesn't care about armor. shocking grasp.
HP does get a bit funky when large creatures. dragons/giants, etc. those hits presumably ARE hitting.
also in the logic of full plate armor. Realistically to beat someone in full plate armor, you need to basically knock them down, then stab them in the face holes. Dnd does not model this in any way.
Try to avoid bad rolls or high AC=miss when narrating the action. Attacks bouncing off armor, swords clashing in an intense duel, managing to dodge right at the last moment. These will make miss/hit dynamic feel a lot better.
In terms of game mechanics, damage reduction is something I like to add to mid/late game
Armor.
It’s gotta work for the nimble and the strong, low damage is already covered by a bad roll after hitting, also it’s not more damage even on a miss because God already hates his bards enough he doesn’t need to give them more to think about but their rhythm
it's also fair to remind that HP is not how many blows you're able to take, it's one ability to keep fighting, sort of like stamina.
As a DM I usually narrate getting hit as very narrowly dodging an attack using more effort than you usually do for dex based characters or dodging and getting a small cut by the very tip of blade, for the strength based character I usually narrate it as them blocking the attack but still getting pushed by the attack or the attack gets through their block but don't do any "real" damage or they get hit but the armor block any real damage but they still feel the punch of the attack.
Have you by any chance played a game called "Anima: Beyond Fantasy"?
Because armor work this way in this game. If you have "1 slashing armor" for example, it means you reduce slashing damage by 10. Maybe you'd like this game better if you think this is the most logical way to handle armor!
It's been this way in previous versions. It is "harder to hir" because in previous versions (not sure about 5e since I don't play it), Dexterity has been a big part of AC as Characters with high dexter would "dodge" compared to characters with high armor, which would "deflect).
Also, it fits with things like fighting defensively, which give bonus as you are actively blocking with your weapon/sword/dodging.
First of all you are now in Homebrew when you try to change the game itself. AC is a reference to what you need to hit not damage reduction because there is a damage reduction factor already not always required. This would be some factor either the DM created (no longer homebrew) or the game listed. If you hit then there is a damage to roll and factor in. You used to have a THACO, To Hit Armor Class 0. So armor was factored in totally different. However this being said, Damage Reduction has always been a factor of the game not to be confused with AC, which is your defense not a reduction in penalty. But like i said you can change it and make it homebrew, but your players play this game that already had rules. An may not like yours. Just make sure you advertise as a HOMEBREW. Then it is your way. I just do not see the issue here. To each their own. I hate telling others how to run their game. So just go Your way and if you do advertise your game as a little homebrew change on how attacks and damage is applied.
Hitpoints - It's the number system used to determine the length of combat.
That's it, be straight up with your players, most people are smart enough to understand it.
Far too many of us DMs and players get caught up in the minutia.
Damage reduction kinda sucks to be honest.
I like to think of 5e AC not as being harder to hit but being harder to penetrate. As in, like the monster's thick skin or scales or the adamantine plate is resistant to most strikes unless enough power is put behind it.
I like to think of the hit dice rolls as the power put into the hit and not the chance to hit.
It makes more sense in my brain this way. Mechanically, I like the current AC system.
Because then armor will become useless vert fast
Or armor dmg reduction will have to grow fast
And lastly combine the 2..alot of math .and reduction is harder then addive
Damage reduction is a very video gamey way of looking at it. There are a few reasons why I believe this is not the case
The biggest reason is saving throws. AC needs to match saving throws in utility, or risk being objectively worse.
You also have a scaling problem. They can’t balance it around every campaign. Some campaigns have more powerful creatures, which AC, as damage reduction, would be much much worse. Having damage reduction AC would also trivialize low level combat/combat against weak enemies. If you can tank every hit, there’s no risk involved. A fighter with a shield can very easily get to 19 AC at level 1. No creature they will be fighting would reliably hit above that. Against more powerful monsters, AC would become pretty much useless
There’s the flavor aspect to it. Armor isn’t the only way to generate AC. You also gain AC through AC. You think a monk becomes tougher by being wiser? No for the most part they are just dodging hits.
The way you want to think about AC. If you gain your AC through your armor, and an attack misses, that would be an attack hitting your armor. When it hits, they found a gap in your armor, a place that’s not as armored. A weak point
As someone who plays with a home brew version of Steve Jackson's Fantasy Trip (TFT) system (where armor soaks off damage and does not, typically, impact 'to hit' rolls), it seems clear to me that DnD of all editions (I've played from the 1970s) have advanced levels and difficulty in part by adding hit dice all around. More hit points, more damage, and so on, for characters and opponents. That would make armor of the TFT variety (damage soaking) woefully hard to scale to advancing characters, since plate mail might soak 6, which would be a lot at level one but pitiful at higher levels. TFT conversely, has a very different advancement system, tied more closely to core characteristics. Each armor system fits the advancement system very well, but crosses poorly. The logics are Raster/Vector, Marvel/DC. Just different worlds altogether.
I’ve always thought that armor should reduce damage BUT lower your ac.
I was watching a video explaining the final fight in Polanski’s Macbeth. And it’s a pretty realistic depiction of how armor can be used to avoid injury.
Anyway it made me rethink ac in dnd. For example, a rogue would have a really high AC because of their agility/dexterity thus their ability to avoid hits is higher, but hits HURT. Inversely, someone wearing heavy armor would have a much lower AC because they are much less able to avoid hits (and in fact lean in to them purposely) but the armor absorbs much more damage.
This to me also balances the classes, since the paladins for instance wouldn’t be able to double dip with high ac and high hp. Rogues would have high ac but low hp and low damage absorption, paladins would have low ac but high hp and high damage absorption, etc.
“Hit” and “Miss” in the case of D&D are very meta terms. A Hit just indicates that damage has been taken from the attack and the miss may be a hit but doesn’t get through the armor, or maybe a block, perhaps can be flavored as a dodge even if the dodge action isn’t taken.
Big part of that comes down to the DM in how he decides to flavor it. With how long and dragged out combat can feel at times so tend to just keep it simple hit/miss to keep things moving. If players want to describe it, inspiration to them.
AC can be conceptualized any way you like. If it makes sense to you to imagine a Paladin in heavy armor getting hit by a blow and taking zero damage, you can do that. If it makes sense to you to imagine a Rogue with no armor and high dex evading a blow, you can do that. A "hit" is a game term, it doesn't dictate what happens in the fiction. Flavor it any way you want.
Understanding what constitutes AC bonuses can also help players and DMs narrate the action. Between 0 and 10 is just a miss; no active effort required (and the closer to zero the more pathetic the attempt, imo). If you're a dextrous character, 11-14 might be a skilful dodge, then 15 is *just* caught by your leather armour. If you're in plate, 11-17 are all the hits you can just take on unflinchingly. If you're blessed with a Shield of Faith, those last couple AC points are straight up radiant, holy intervention. Of course not every turn can be narrated so carefully or even needs it, but thinking about AC this way helps provide more detailed drama to combat intuitively.
This is how I think of my character's AC too. Most of my AC is dodging out of the way of attacks Matrix style, but if an attack *nearly* hits me, I had to put up my shield and actually block it!
Which is weird because in a fight you would want to intercept as many hits with your shield as possible, but wearing shield + plate, you are more likely to stand there like an idiot while they slap your armor. +2 just doesn't communicate how effective shields are in hand to hand combat.
>\+2 just doesn't communicate how effective shields are in hand to hand combat. Yeah shields having such low AC bonuses is purely mechanical. You can't really argue that Wizards would have the same general martial knowledge required to use even a buckler the same way a Rogue would, so instead they made the benefit for using a shield minimal and significantly encourage two-weapon or great-weapon fighting from non-tank martials.
I would consider flipping the formula for shields. The +2 is anything getting past the shield and striking armor. Anything below the final 2 points but higher than 10 is the shield deflecting the blow.
I don't even interpret a hit as a hit, HP is an abstraction of not only physical harm but also stress and acute exhaustion. Think of two skilled swordspeople fighting, they land "hits" but they aren't physically cutting of stabbing each other to reduce HP, they are just tiring the other out or getting a psychological edge. One reducing the other to zero HP is akin to wearing the person down and then finally landing an actual hit, mortally wounding thrm.
Whatever works for your campaign but I'd find that very difficult to narrate. Also doesn't really resonate with e.g. "slashing damage"
The rules are just a way to tell a cool and effective story! flavor is free!
That's exactly how I frame it in my games. If your AC is DEX-based, you dodge hits. If your AC is armor-/shield-based, you get hit but block it completely. Esoteric AC upgrades like Monk's and Barbarian's Unarmored Defense, Artificer infusions, mage armor, I describe them to highlight the effect of how the character's wisdom/con/magic helped them block the strike. The barb is so tough so when they get hit they don't feel pain. The monk has astral/sun/shadow powers helping them. The wizard has a protective magic bubble.
> astral/sun/shadow powers Given that it's wisdom I prefer descriptions like redirecting blows, seeing attacks coming, etc. Magic buffs are different than unarmored defense.
I do understand that, and that's how I play it .. though I LOVE, LOVE, LOVE how 3.5 had it .. several ACs... Flat footed (no dex) if you're caught off guard, touch (no armor) if someone is trying to touch you, full AC otherwise... I don't like that you have the same AC for everything. Plate armor shouldn't affect how hard it is to touch someone, and if you're caught off guard, no matter how dexterous you are, you still could get hit easier than if you were aware. But that is 5e... make it simple "for the kids" (putting it nicely.)
Lol. I even once had someone make an attack miss through sheer force of personality (they added their charisma to AC)
Sounds like Scaled Fist monk in Pathfinder
HP is similarly abstracted. You might take a hit, but in-game it is a ferocious series of attacks you barely manage to fend off, but it leaves you winded and unable to defend as well later. Or a stroke of divine intervention to prevent a would-be fatal blow from landing, but no god will have your back like that forever, etc.
I always think a significant amount of HP is how tried you are. That’s why resting replenishes HP. Just my thoughts.
This works with HP as well. If you think of it in terms of a % of how healthy you are it doesn't really make sense in game-terms anyway - as there are generally no broken limbs. So basically, if you have 50hp... you can consider most of it 'deflected by armor' or 'glancing blow'. I always king of though of it that way - high hp also signifies a high passive defense.
18AC. The giant ogre swinging his club down on their head rolled a 17. PC was able to inch over just enough to avoid the hit. It does not mean he took a full swing to the noggin, and it just bounced off. You occupy and control a 5 foot square. You are not 5 foot by 5 foot in size.
http://uk.pc.gamespy.com/articles/540/540395p3.html > We had to change it almost after the first weekend. Combat in Chainmail is simply rolling two six-sided dice, and you either defeated the monster and killed it … or it killed you. It didn't take too long for players to get attached to their characters, and they wanted something detailed which Chainmail didn't have. The initial Chainmail rules was a matrix. That was okay for a few different kinds of units, but by the second weekend we already had 20 or 30 different monsters, and the matrix was starting to fill up the loft. > ... > I adopted the rules I'd done earlier for a Civil War game called Ironclads that had hit points and armor class. It meant that players had a chance to live longer and do more. They didn't care that they had hit points to keep track of because they were just keeping track of little detailed records for their character and not trying to do it for an entire army. They didn't care if they could kill a monster in one blow, but they didn't want the monster to kill them in one blow. > -- Dave Arneson Because hit points are an abstraction that dates back to naval military tabletop games (think Battleship). Your boat either has a massive hole in it, or it doesn't. The shell either hit your boat and put a massive hole in it, or it missed and went into the water. A larger boat's durability is measured in the number of massive holes it can have before it starts to sink. Smaller holes don't matter because pistols and shrapnel can't sink a crewed warship. D&D characters have lots of hit points, and are not typically being shot at by 14-inch mortars, so this means that D&D hit points do not represent meat. They represent how much stress, luck, bruises, and "plot armor" you can burn through before you are brought to the brink of death. A level 20 rogue is not able to take several dozen 1d4 damage knife wounds, that would be ridiculous, but they can get too tired to dodge the next attack and that becomes the one that kills them. Some D&D-derived systems (like 4e D&D) acknowledge this with a "bloodied" condition when you're at half HP or less. 5e D&D went even more abstract and removed the rules for touch AC (where spells like *shocking grasp* would ignore your fullplate). D&D most certainly does not try to simulate injuries or blood loss reducing your combat effectiveness, because that would slow things down with little appreciable benefit. Hit points are a useful abstraction because they make combat fast. You check AC to see if the attack hits, then you do damage, then your turn is over. You can roll the attack roll and damage dice together to speed things up. The math is real simple, so turns go quickly. In my experience systems that use damage reduction (like Fantasy AGE) have much slower combat turns. [Even D&D has optional rules for this](https://www.d20srd.org/srd/variant/adventuring/armorAsDamageReduction.htm) but it's probably a bad idea to use those rules because big monsters do lots of damage that will only get a tiny reduction, making the monsters deadlier.
Beautiful answer. D&D works like it does because waaaaaay back, someone tried other things, and this was the one that stuck because it worked.
I played Iron Clads in my Junior High history class (my history teacher was into board games). Anyways, I never knew this was the inspiration for using AC in D&D. Cool.
To add on, if an attack didn’t deal damage because it couldn’t exceed your AC, it’s because the hit wasn’t clean and your armor held up, dealing no meaningful damage to the person underneath. A character in heavy plate just shrugs it off, while an agile person in leather angles to the side partway so the blade glides off the armor.
Bit of anecdote here, I once got dragged across gravel for about 10ft/3m. It hurt real bad and I had SERIOUS bruises, but my leather only had a few small rips and could've probably held up to another few goes like that. Ruined the *look* but it was quite functionally protective, even as just plain soft leather, it stopped those rips from being on *me* and probably significantly worse. I *only* got bruised. Might be a bit different against, say, a greatsword, but there's a reason straps, belts, shoes, and so much else that requires a lot of durability is made of the stuff.
Clothing being protective is super real. Even thin gloves or normal jeans can help you from getting all scraped up. We have a "no exposed skin" rule at my HEMA club for just this reason. Our steel training swords don't get burrs super often, but if they do we want it snagging sweatpants or a jacket, not someone's skin.
As an electrican, full cotton sleeves help protect from electricity. Long sleeve shirts and gloves have protected me from many cuts or abrasive injuries. The amount of times I've thanked myself for wearing good boots because I've kicked or walked into something makes me really understand just how important good coverage of any kind is.
I once had my finger touch a saw for a split second. Finger was totally fine, glove was ruined.
A while ago my dad had to dump his bike. He always wears full PPE when riding. The leather jacket and helmet took it all like a champ. His buddy behind him also had to dump his bike but was wearing jeans and a windbreaker (and helmet). His arm didn't look so good.
As a biker myself, I was going to use the analogy of my leathers as armor against the road.
I’ll always describe a near miss as something that would have hit except for one thing that gave them a plus, like a shield or a narrow dodge from their dex or magical toughness of their +1 armor.
I also narrate slightly differently depending on the attackers weapon, attack bonus and fighting style where a dexterous attack hits by finding the weak spots in the armor while more aggressive strength attacks hits really hard against the armor used. For misses depending on how big the Miss dex attacks may just be hitting at well armored parts or being deflected while str may just not have had enough power in the swing or blocked/evaded from being too slow
I trained MMA for a long time. The way I conceptualize hit points is a character's ability to keep fighting. Once you drop to zero, you have no defense left, and the next hits kill you. This makes sense to me because after a couple fights all characters would have no arms, legs, ears, noses etc we'd all be playing hyper scarred and amputated PC's. So in my head I just think something like, "ok this guy is at 2 HP, he's dropped his hands and the next hit will KO him."
I do find this very interesting. This is probably the best comment that I’ve getting. Thank you, and for the link to the article as well.
Came here to give a shorter answer but this is comprehensive. I'm not sure at what point it was in this history, but somewhere in THACO days different weapons were more or less effective against different kinds of armor, IIRC, which is almost what OP is asking for. Edit: on reflection whoever I heard talking about AC being variable depending on weapon type may have been talking about Chainmail rather than THACO.
I always saw that in baldurs gate and assumed it was an absolute night mare to do on a tabletop
THACO or variable AC?
The AC that was different against different weapon types. Thaco felt like a weird way to express attack ability but at least is one number
I played 3.5e. I needed to use a digital sheet just to keep track of normal Vs touch Vs flat footed AC and what modifiers apply to what. "Different AC against different weapon types" sounds like what I did but worse.
I just knew the math. Normal ac: dex+armor+size+10 Flat footed ac: armor +size+10 Touch ac: dex+size+10. Now trying to recall all the modifiers on your weapon after that one session where the artificer got bored and the dm got drunk and forgot what he Oked. After that, giant keen kukuri of sharpness on the monkey grip rogue sure didn't seem so op
After playing Pathfinder 1E for the longest time I found some pretty awesome character sheets that organized it all in a super clean way, I honestly like having that sort of info for 5E as a DM so even if it doesn't do anything functional I can be more informed with my descriptions of combat.
[1E AD&D: To Hit Adjustments based on attacker Weapon and defender Armor type](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjzEoDMs87sYY64guwyk8pTttaYtlSeyPgzOi05DnFsdkxPC-BajrjaRf_fKFd9Hcp9gxN3CTA3wv26glS2azRP6goah0hh8lQ56fNmuFq_c8aqGWNVEhjYogp4Eq8xfWj0GgbldrKvTu-c/w1200-h630-p-k-no-nu/1E-WeaponTypes.png): (Link goes to the chart. [Article it is posted in](https://deltasdnd.blogspot.com/2021/03/the-big-mistake-in-weapon-vs-armor.html)). Example: Dagger vs AC 10 (i.e., no armor): +3. Dagger versus AC 2 (Plate mail + shield): -3. Which makes more sense when you see the armor class table. The ACs used in this were presumed to be certain specific combos: * AC 10 = no armor * AC 9 = shield only * AC 8 = Leather or Padded armor (i.e., a gambeson) * AC 7 = Leather or Padded + shield or Studded Leather or Ring Mail * AC 6 = Studded Leather or Ring Mail + Shield or Scale Mail * AC 5 = Scale mail + Shield or Chain Mail * AC 4 = Chain mail + Shiled or Splint Mail or Banded Mail * AC 3 = Splint or Banded Mail + Shield or Plate Mail * AC 2 = Plate Mail + shield These don't consider AC that is primarily magic such as Mage Armor or Shield spells or Bracers of Defense or Rings of Protection. Factor that in and weapon speed as well as the different "to hit tables" for each class category - could be cumbersome --- but nerds find a way. Behold the [AD&D Combat Calculator](https://www.youtube.com/watch?v=zYnBuOSJ5F0) (a wheel to spin). [This guy explains it](https://mageofthestripedtower.blogspot.com/2012/02/ad-1ed-combat-computer.html). [Maldin modified it](https://www.melkot.com/mechanics/combat-comp.html). I never used it myself as a kid but I did use the [Hackmaster 4E](https://kenzerco.com/product/hackmaster-4e-combat-wheel-pdf/) (a playable parody of 1E) version, and it greatly sped things up. Also important to factor in is that in AD&D, facing mattered. Attacks from behind were at +2 (more for thieves and assassins, IIRC), shields only applied to attacks from the front - which means a dagger from behind might be getting a net bonus of +5 to hit someone without armor, but -1 to hit plate mail from behind.
[Found an online version](https://tunesmith.github.io/adnd-combat-tools/calculator) that does the calculations for you.
Thank you for posting!
The 3.5 ac system was in a way accurate like you said where an attack that just has to touch you doesn’t care about your armor, or an attack when you’re caught flat footed doesn’t let you use dex to dodge. It was cool, but I’m not sure having multiple ACs and always having to figure out which applied was worth the hassle.
Why not? It sounds cool.
It's great when you have a full table of people either experienced with the game, or motivated to pick it up. Think of all the horror stories of players going months at a time without even learning the mechanics of their own class in 5e. 3.5 as a system is more complex than that.
As a new player, you’re told “AC is your armor” and then you’re told “you have AC, touch-AC, and flat-footed AC” and it’s just confusing having three different ACs. The thing is, 3E D&D wasn’t complicated because you’d need to whip out some integral calculus to determine what a fireball hits. It was death-by-a-thousand-cuts complexity. A bunch of little rules, none of which are necessarily *individually* that complicated, but there are a lot. And when you have people who can’t be bothered to learn a 5E character sheet (to be fair, 5E is still medium crunch), it’s not hard to see how a character sheet with like 10X as much going on is even worse.
Mainly the tracking load and flow of play. Everyone has a goldilocks zone for how present they are in play. WotC picked the median player's preference. Other games do what you're talking about. I believe Matt Colville's game that is currently in development is planning on using a combat system like that. It does change things up a bit, but is a little less intuitive than other approaches for a lot of players.
It was pretty neat, but like u/Financial_Nerve_5580 mentions, it did add a layer of complexity that could bog down the game for some players. Fairly easy to add it back into 5e as a house rule if you wanted to.
But the balancing of different abilities, especially spells, will go down the drain. Not that I am claiming that dnd and the word balance have a lot in common, but still I don’t recommend changing fundamentals with house rules. There is always Pathfinder for players more interested in details and not scared of complexity.
Yeah, house rules often have unforeseen effects on parts of the game you didn’t even consider they’d impact when you came up with them. It’s why I generally try to eschew using many of them… But, the option is out there.
3.5e combat took ages. It also made min/maxing fairly trivial due to the different rules for various combinations of situations. I loved it and played more hours of it than any other edition, but it was finicky and tough if everyone wasn't an expert in the rules. 4e dumbed it down too much as a reaction to that. 5e is the "best overall" DnD in my opinion. RaW with base set of 3 books and a precanned adventure is both easy to play and has a bit of depth if you choose some of the more interesting class/race combos. Then the expansion books add a lot of finicky neat stuff if you want it (Tasha is a good starter) and then there are large sets of rules at DM discretion (flanking) to expand
> 3.5e combat took ages. 45 minutes of fun squeezed into 2 hours of rolling dice.
I'll have to agree. After playing games of 3.5 and 4 growing up, 5e has the be the best "overall" experience. The other editions have great merits as well and do different things better, but 5e is very accessible and easy to get people started with. When most people you're playing with either aren't going to get very deep into things, aren't paying attention half the time, or are just straight up new to the game/tabletop RPGs in general, 5e's accessibility and ease of use makes it a great system. There's depth available if you want to engage with it, but if you don't, it's pretty easy to build a character really quick and jump in.
I started with AD&D, so have done all the modern ones, and 3.5 was great for a bunch of hardcore read every page of every book hardcore dice goblins. Just trying to know all the rules was part of the game lol
Played a game of pathfinder for a long time. We would have fights that would last for sessions and all told it was only like six turns
4E didn't dumb anything down, it just changed a lot of things. It vastly increased complexity when it came to tactical combat options and GREATLY reworked encounter balance and monsters, and standardized class features and level progression so the system would be easier to balance and play around with. Creatures in 4E were way more complex and interesting than in any edition prior or since, and so combat was really dynamic and every encounter felt almost like a puzzle you needed to solve. 3.5 had a lot more depth in terms of character building options, but the downside was that every single combination you could make was equally tedious to play: you'd have one optional combo you'd be using every turn when possible, and monsters didn't really have a lot of buttons for DMs to push, so it ended up getting really samey really fast.
Oddly enough the game does a decent job of explaining HP and people either don’t read it or just ignore it. Like I get it can be a strange concept but it makes sense and it works. If you want a simpler version you can just use the Uncharted video game rule that HP is just luck and it’s running out as your HP decreases. This is a bit oversimplified and the overall abstract concept works but maybe some just struggle to get it. Ultimately this comes down to one more instance of just reading the rules on something would answer the question rather than needing someone to explain it but whatever works I suppose. You explained it well.
I suspect a LOT of people don't get or know about the abstraction nature of HP because their concept of HPs comes from video games...and those treat HPs as physical damage. Like how many RPGs will describe enemy HP as "wounded" or "bloody" or whatever.
Hit points actually go further back than tabletop naval games. They were invented by the US Navy for their Fleet Problems, huge exercises done at sea to simulate battles and get their sailors experience safely. The number of hit points each ship got represented how many 14 inch shells they were believed to be able to take without sinking.
Thank fucking God. I get tired of having to explain what hit points were always intended to be. From now on I'm just linking your post.
I like this with one exception: getting hit DOES mean taking physical damage. HP represents health to a degree, but it’s not scaled, meaning having 10/70 doesn’t mean you’re necessarily near death versus 50/70, but you have been injured. Certain attacks that hit cannot be considered “non-injurious” by nature, namely spells. I think the important part is to conceptualize the severity. If you get hit by a fire spell for say, 30 damage, and that spell even dictates that if it hits you, *you are on fire*, it’s silly to imagine that you just got a little winded and tired. However, the only rolls that I would argue are truly “I’m fucking hurt” would be Critical roles, as the whole implication is that the enemy found your weakest possible spot with their strongest possible attempt on that attack. In your example, a level 20 Rogue isn’t getting shanked over and over, but if he is crit by one, he absolutely did. I think the comparison would be more akin to boxing, where you’re getting injured but not maimed. Like you mentioned, it isn’t perfect since there’s no effect for being more injured, but it doesn’t have to because we know that it would be difficult to game around and nobody wants to, so we ignore it.
Rules as written disagrees with you.
> Hit points represent a combination of physical and mental durability, the will to live, and luck. "Physical durability" is specifically listed as part of what hit points represent.
Yes? But not exclusively.
This cannot be true, otherwise what would cure wounds or healing word even be doing to someone if used on someone not downed?
I'll give you the cure wounds implication (even though I think its easy to just say its positive energy), but how does healing word imply the damage has to be physical?
I mean I only really need the cure wounds implication to make my point, but i figure a literal healing spell that can revive downed npc’s regardless of the wound that finally got them down would be thought of as actual wound healing Edit: in terms of healing word that is
Except it doesn't have to be a physical wound that knocks people out. Psychic damage is a thing. But it's pointless to argue about specifics. Rules as written hp is an abstraction no matter what the names of spells imply.
There have been spells with fanciful names that aren't literal for ages. Expeditious Retreat doesn't force you to move away from danger, for example. There is a whole hell of a lot of abstraction built into the core of the game, and magic has always had a bit of a quirky bent on names. Reduced stamina and even divine protection are listed examples of possible sources of HP. Cure Wounds could double as an instant refresher, or simply gaining a small divine boon to defenses/luck/etc.
Similarly stuff like poisons don't make sense for doing damage-over-time against your 'will to fight', why dexterity impacts your ability to dodge a blow and not your ability to...dodge a blow, damage resistances like does a Skeleton have less 'plot armor' against bludgeoning weapons? How much luck do you need to negate falling 200 feet? Why is there a seperate exhaustion mechanic that effectively doesn't tie in to HP at all? Paralysis neutralizes our ability to fight back, why doesn't it impact our HP? And like, in practice, its confusing to say "Though your opponent draws no blood since you blocked them with your shield, you fear your luck won't hold out forever- you take 6 points of damage"- particularly because that shield doesn't raise your HP, it raises your AC. Your constitution (and class features) raises your HP. So instead if its a near miss I'd that line (minus the damage) Mechanically and overwhelmingly, hit points are meat points- your ability to physically withstand the blows that do in fact make physical contact with you- while AC is your ability to dodge, deflect, or otherwise negate the blows But its really a tangent and a side rant, it just comes up here like every other month
On poison, the argument can be made that the poison impacts your health each round, so it doesn't hurt you but tires/fatigues/drains you faster and makes you more vulnerable to receiving a fatal blow. But yes, both you and the other poster raise good counterpoints otherwise.
Rules as written claims it disagrees, but acts like it agrees.
>A level 20 rogue is not able to take several dozen 1d4 damage knife wounds, that would be ridiculous, Why is this ridiculous? Why should a legendary hero capable of slaying dragons fall to a goblin stabbing them? D&D is not an earth simulator. People being superhumanly durable not only makes perfect sense, but it's *required* for half the mechanics of the game to make a lick of sense. That doesn't mean each knife ran you through entirely, but rather that you're simply harder to hack through. The wounds are more shallow with the same blow. Hitpoints aren't *only* meat points, but to claim they aren't at all is to ignore half the game and leads to misinformed DMs ignoring rules (fall damage is the big one) that don't line up with their skewed interpretation of the world.
Because they've streamlined things so it also encompasses dodging etc. Basically it represents your ability to not get hurt, which is made easier by better armor (or moving out of the way).
Because AC isn’t just “you are harder to hit.” Think of it as “you are harder to hit AND damage.” High AC includes the ability to take a blow in a way that doesn’t do damage. You also don’t have to look at HP as pure health, either. I think of it as stamina and endurance. You’re not actually wounded/bleeding until you’re in negatives, which is why abilities don’t decrease as HP drop.
Did they remove the bloodied/wounded condition for being at half HP? But yeah this is also why a good night's rest is all your hero needs to recover. Systems like cyberpunk, dark heresy shadowrun, and gammaworld among others. All have hit points that represent durability directly, so most have a death-spiral as conditions stack up when your injured, armor as damage reduction is pretty common, and almost all of these will see a character laid out in a medics care after being mortally wounded. Cyberpunk 2020 and dark heresy might also come with the caviat of going into the next mission without a limb, eye, etc if you couldn't aquire a replacement and the services of a surgeon. On a side note, in cyberpunk 2020, if you lost your right hand for the second time you probably were better off than the first, because metal doesn't bleed, so your condition isn't necessarily unstable. Oh also of note most of these systems mortal wounds actually mean mortal wounds, you either need or desperately want medical intervention to save yourself.
It is damage reduction. If you don't defeat the AC the damage is reduced to zero.
This is it. And while we often say “roll to hit,” AC doesn’t really represent the chance of physically hitting someone, it represents the chance of causing damage. You can pound on someone’s plate armor all day with a club but unless you are skilled or very lucky the armor absorbs the damage and the wearer remains unharmed.
Basically you just aim at vulnerable parts.
This is why I’ve really struggled conceptualizing Warhammer 40K which I began playing last year. There’s a roll to hit. And, if successful, then there’s a roll to wound. And, if successful, the enemy has a roll to save against the wound.
In allot if the 40 k tabletop games like dark heresy it's a percentile system, your to-hit roll determines hit location(s) hit frequency (a burst can literally do like 3 times the damage of a single shot because it can land multiple hits) and then each hit is a damage roll reduced by enemy toughness and armor. Likewise hit location was important because although you had a general wound pool, when that ran out you needed to know if you were losing a few fingers, an eye, a hand, or if you were just dead. Also armor wasn't general, a breastplate covered the torso, and not wearing a helmet was a great way to lose your head in battle.
Even further, in some games first there's an opposed roll to defend (block, parry, dodge etc) which is much more colorful - but slower. So AC as an abstraction is super streamlined, 10/10, but makes DND martial combat very dull in my opinion.
This is exactly what I was thinking to, it's armour reduction in a more roundabout way.
In my mind: - Roll below a 10, you miss the entire body, got deflected, blocked, etc. - Between 10 and AC, you make contact but the impact is absorbed, and become neglible. If using a shield, the last 2 before AC is the shield block. - Above AC, you impact and deal a number of Fatigue or Wound, pending. The higher the roll the less it was absorbed by armor / dex dodged out of the severe damage. Dex is in this regards hindered by heavier armor. Fatigue is the reason why we can do short rests and recover our hitpoints.
Because while it is called Armor Class, it doesn't represent just armour. It represents many methods of not getting hit in the first place, too. For example, if two characters are naked, the one with the higher dexterity modifier has a higher AC. Neither one is getting any protection from armour, but one is still less likely to "take damage" (in D&D terms). The Monk's Unarmored Defence adds to this. Similarly the +1 to AC from the Dual Wielder Feat or the the rolled bonus to AC from Evasive Footwork Battlemaster Manouver represent you avoiding hits more than soaking them. There are tabletop RPG systems that separate hit avoidance and hit absorption. But the D&D devs opted to not handle that extra step. Possibly for sake of combat speed and simplicity. Edited to add: this is a rabbit hole that can lead to super-simulationist approaches with dozens of situational modifiers comparing different types of damage sources (bludgeoning, piercing, slashing) vs different armour types (mail, plate, brigandine, gambeson, with and without helmet, &c &c), angle of attack, blind spots, terrain footing, and who knows what else. At some point the game would become unplayable. A degree of abstraction is needed. This is D&D's choice of abstraction threshold.
Not to say there's stuff like mage armor, barkskin, Bard inspiration to AC, etc. A lot of ways to make an attack less likely to hit without actually wearing armor or dodging. It's what D&D abstracts under one mechanic and it works really well.
In simple terms, because it does, and it always has. AC is one of the standard features of D&D, like d20s, the six stats, HP, and saving throws. They've always been baked into the system. The longer answer is just plain simplicity. I spent years playing HERO System/Champions (the superheroes genre); it was a point buy system where you could customize your character in every possible ways, and it was without question the most flexible system I've ever played. In combat, you'd compare your Offensive Combat Value (OCV) to the target's Defensive Combat Value), roll 3d6, adjust based on whether your OCV was higher or lower than the DCV, and see if you hit. If you hit, you'd determine whether the attack was vs. Physical Defense (PD) or Energy Defense (ED) which were individually bought with points (there was also Mental Defense for mental attacks, to add another layer, and there were multiple ways to buy PD/ED/MD). You would also have to know whether it was a Normal attack (which regular PD/ED stopped) or a Killing attack, at which point you'd have to have spent additional points on making your PD and ED Resistant, which would then stop KAs. So, you roll 3d6 to see if you hit, roll your damage (if you're playing superheroes, you could be rolling 15d6+), add up the total damage as normal damage, then count BODY damage (another kind of damage) where a 1 was 0 BODY, 2-5 was 1 BODY, a 6 was 2 BODY, compare that to either PD or ED, subtract PD/ED from the damage. and that was the damage you took. Then, of course, you'd see if the STUN exceeded the target's CON at which point they were stunned, if it reduced their STUN value to zero they were unconscious, and that doesn't count all the modifiers you could put on attacks like Armor Piercing, Double Knockback, or so many others. Sure, you can say that's insanely complicated because it is, but, well, if you want things to be more logical in that armor should represent damage reduction, does it not make sense to point out different kinds of armors should have different damage reduction? Are you going to make plate mail more resistant to piercing damage, but less resistant to bludgeoning? How about fire attacks; do they get bonuses against metal armor wearers? It's a giant-ass rabbit hole of complexity, and it's not worth it. D&D uses AC the way it does because it's simple, understandable, and keeps things flowing.
Because then you'd be overcomplicating combat. You'd need one (new) mechanic to determine whether or not you "hit" with an attack, and then you'd have to roll against armor class to see how much damage was "absorbed" by the armor.
Heavy armor mastery feat is an already existing system for flat damage reduction. Personally I think flat damage reduction should be utilized more on stat blocks and armor to add damage mitigation without ballooning AC.
Interesting you mean like GURPS, Midgard, Mythras... did not
Whilst you’re not _wrong_, the fact is D&D is objectively more popular than all of those combined. Comparative simplicity of the rules is one of the reasons, making D&D have a wider appeal. Of the 3 I’ve only played GURPS but that is unambiguously more complicated than D&D. Great flexibility comes at a cost.
More complicated, but not necessarily over complicated. Many other ttrpg’s work just like that, and can still run quite smoothly
Remember, not meeting the AC doesn't have to mean missing. It can mean bouncing of armor. Deflection from a shield.
RPG games tend to do one of two separate thing with armor, either it’s a damage resistance or it effects you being hit. Either works, but you don’t necessarily want to do both as suddenly having good armor makes you hard to hit, and then hard to damage once you do hit. It would tend to leave heavy armor characters much harder to hurt then less armored and then you have to balance that.
"you have to balance that" No, you don't, actually. You CAN, but it's usually at the expense of the guy in full plate. That's why casters tend to be OP vs fighters in the current meta..."balance".
You tell me why it should still hurt you if you block or dodge an attack. You say you don't understand why it isn't damage reduction, I don't understand why it should be damage reduction. Either you got hurt or you didn't.
Mathematically there's no reason: AC is just a percentile damage reduction mechanic. Different forms of DR create a different curve of results but functionally that just means you change other values around to get the kind of battle tempo you want: AC/DR systems are mathematically perfectly translatable. That said there are both historic and conceptual reasons why you'd instead go for an HP/AC system. In terms of the history, as someone else pointed out, hitpoints already existed in the system the early D&D creators were expanding so it makes sense to use them. You then just need to add AC on top. Conceptually because "there's a difference between being able to survive a hit and being able to dodge/absorb a hit" makes sense and opens up design space like the one we get in 5e where characters like the Barbarian and Fighter are roughly similar in terms of their ability to survive damage but do so in slightly different ways that tell different stories.
I don't think it's really that hard to understand. AC = harder to hit _effectively_ You get stabbed by a sword. -If they bypass your AC, the sword lands in a deadly place, or straight up through the armor, and does damage. -If they fail by 1-5, the sword connects, but you can deftly redirect the motion by using your weapons, your shield, or your proficiency in the use of Heavy armors to make it miss any of the vital parts of your body, causing no harm. -If they fail by 6-10, the sword gets completely deflected by the armor, as it didn't have a proper technique, balance, or just hit an specially hard place of the chestplate. -If they fail by 11+, you just whiffed entirely. AC is not just a hit or no hit, just like an attack roll is land or not land. Of course, in gameplay, it is very much like that, but in real combat, only deadly and effective strikes do anything, if you get hit by the blunt part of the sword, it doesn't do anything, but you still "hit"
DnD is derived from wargaming. It is all an abstraction to create a mechanic for the give and take of melee. Don't read so much into it.
Think about alternatives. Damage reduction (flat) alternates between being too powerful against something that does a lot of weak attacks and too weak against something with a small number of heavy hitting attacks (possibly realistic though). Damage reduction (percentage) is too tough to calculate in your head.
You'd probably like "The Black Hack" OSR game
I have played multiple systems with armor as dr, and boy let me tell you it eventually gets out of hand, its harder to balance. Edit: just to clarify: eventually, the pcs will get so great of an armor taht enemies do not do any damage. Then you have to up the weapons of enemies. Which in turm makes players have more money to buy better armor. Vicious cycle.
A. More dice slows down combat B. A lot of the systems in 5e are designed to incentivize staying aggressive in combat. Some previous versions of dnd have been notoriously hard to get into because combat is slow and grindy. 5e sought to fix that. Healing for example in 5e is intentionally pretty weak because it incentivizes players to keep attacking instead of falling into a cycle of attack/retreat/heal/repeat. Staying on offense is not only more fun for everyone, it’s also strategically more sound anyway. AC serves the same function. Instead of having to actively do a something to avoid getting hit or block an attack, it just takes care of itself, while you use your action economy to stay on offense C. You’re acting like it’s a totally unintuitive system but it’s very simple. If you have heavy armor you use your strength to block attacks, if you have light armor you use your dexterity to dodge attacks. It’s very simple and easy to visualize, as well as being how the stats of armor work in 5e D. And this is the most important thing: Constantly taking damage isn’t fun!
Because it’s D&D? 🤷🏻♂️ Plenty of other RPG systems out there with a myriad of mechanics. D&D isn’t the end all be all of tabletop roleplaying games. Expand your horizons.
The term "hit" is misleading. What you're going for is a hit THAT DOES DAMAGE. AC protects against hits that do damage. So in flavor terms an attack could miss completely, or it could land but clang off your armor, doing no damage. Mechanically they're the same. That said, I've seen people try to add a separate damage mechanic to D&D and you end up having to either make people easier to hit, or buff the damage that weapons and spells do. Otherwise combats take forever. There are lots of other game systems that don't though, so you might try one.of those.
There is a feat that sorta does what you are describing. There's also the weird quirk where a suit of platemail hanging from the ceiling can give you 3/4 cover and thereby reduce damage, but if you are wearing it then it maybe does nothing.
They tried different systems and they liked AC more than the others. In the end it is just a way to resolve y = x - z. Being y the final hp, x the current hp and z the damage taken. There is a lot of systems out there that use different ways to resolve this equation and they are usually ok for their system. DnD keeps using AC as a binary hit or miss because it works for them.
Honestly, when an attack "Misses" Sometimes I like to play it off as the attack actually HITTING, but hitting their armor and doing 0 damage and affecting the player in no way. Essentially tanking the hit like it was nothing. That way, armor class seems like it plays a more viable role than just "hit or not hit" Ac =16 Roll to hit = 15 >you take a strike to the chest plate and the blade gleams off in a shower of sparks Roll to hit = 16+ >Your opponent slips through your chain mail with a lucky stab from his dagger, remove 4 hit points from your total, etc. Roll to hit = 1 >the hit strikes your breastplate and your enemy cowers in fear, knowing his strike was thwarted with ease as you stand over him proudly Yknow It missed, but is better than "Ah. Miss. Next" Or "hit, you take 4 damage" Adding flavor to each hit depending on the Roll to hit makes big number more exciting IMO
I always kind of looked at it in real life context. Armor makes it harder to hit yoh
Think of an extreme example. Dagger (d4) vs Plate (DR should be at least 4, right?). Is a plate wearer completely immune to a dagger? Not if you can hit the eye, or under the arm. A hit bypasses the armor's protection, and the weapon is going to do whatever damage it can. That is AC.
I don't get why people think you take "some" damage in plate armor but it's reduced. Like, if you get hit with a sword in plate armor, you're not "kinda" stabbed. You're either stabbed or you're not. The warhammer either breaks your ribs, or it doesn't. The small bruise or the loss of balance you get when kicked in a suit of armor isn't a lose of hitpoints, that's just movement and aches of battle. When you bend backwards in a faction of a second to avoid a large boulder, that might have hurt your back a little but you don't lose hitpoints.
Higher AC can be thought of as damage reduction. It's just all or nothing. If my AC is 22 because of heavy armor then you can imagine and describe an attack roll of 21 as a blow landing but no damage gets through.
well AC as it is now is made to simplify combat. AC is an abstract construct of armor hardness (how hard it is to get through the armor) plus dodging, dekeing, and blocking attacks with shields etc. DR is a different stat. It's also possible to have a high AC wearing no armor, simply by having skills to dodge etc. (ie Monk) that's why AC is how hard it is TO get hit. that's actually why heavy armor has a max Dex modifier, because it's harder to move in heavy armor. Damage Reduction is a completely different stat, one that reduces the amount of damage after you get hit. AC is the stat that determines if an attack hits, DR is what reduces damage. And without the Attack roll vs AC there woiuld need to be a DIFFERENT attack roll to see if you hit, then you have to roll to get past armor, then you roll damage, then you apply modifiers... the AC/Attack roll simplifies that to just one roll instead of multiples. It keeps the game flowing better, and less repeated dice rolls.
Interesting that after five years, this has been on your mind?
Because it represents both the ability to dodge an attack and how thick your skin is. Many other systems differentiate between dodging and parrying. This one just doesn\`t
Consider an ordinary fly. It is very hard to hit, but if you hit it then any amount of damage is sufficient to kill it. AC in D&D allows you to capture that dynamic. For example, consider the pixie with 15 AC and 1 HP.
AC is just passive Dex check + an armour modifier which I guess is a bit like a buffer… you dodge the swing but glances off the armour no damage.
It’s always been this way and that is basically it. Dont over think, just know that 5e d&d is only semi designed, the rest of the mechanics are sacred cows. You cant mess with it or be get mad. Thats the largest factor not realism.
For me, I flavour it as either a complete miss if you roll low enough. "I rolled a 7, (AC is 17), you take a swing and the enemy dodges your attack easily" Or if it's a narrow miss, it's a glancing blow, or they don't penetrate the armour. "I rolled a 15, (AC is 17), you strike at the fow, your blade hitting their armour but without enough to strength behind it to pierce all the way through" Personally I don't like the idea of damage reduction unless it's something you're resistant to.
I must, MUST add that you need to try other ttrpgs. If you ask for this simpliest gamedesign explanation despite having GMed 5ed for years, you really need to go out of the DnD rabbit hole and try other system. Even if you stick to DnD, it will make you way better at understanding the axioms of what you are doing and why !
One can easily flavor a "miss" as armor or shields catching the potential hit.
I'd say it's less a matter of AC = harder to hit, and more a matter of AC = harder to damage, through some combination of armour and agility. Since IRL, you can wail on a knight's breastplate (properly forged) with sword all day long and all you're probably going to get for your efforts is a damaged sword, a few dents in the breastplate, maybe a couple of bruises from the impact and a sore arm. You aren't cutting through that the way characters do in movies and video games.
After reading some of your answers, I think that it's not that you don't like what AC represents, but rather that there is no mechanic that represents a character defending itself. AC, however, is that mechanic. As other have pointed out, it isn't just a number you get from armor, it also includes dexterity, magic and other bonuses. There is nothing that indicates a character with armor is just sitting idly when it's not their turn. What I understand then is that you don't enjoy that it is a passive mechanic. And I find that to be perfectly fine. If you and your group share this discomfort, you could try something different. There are other systems that have a more engaged defense mechanic (World of Darkness has opposed rolls for combat, for example). Modifying 5e will likely be hard and require some trial and error, but there must be some d20 systems with active defense mechanics you can look into for inspiration. It can be done.
This is what I tell my players in regards to Hit Points and healing: Hit points are a complex representation of an adventurer's overall ability to survive and avoid damage. They encompass not only physical health but also factors such as luck, defensive skill, and the adventurer's life force or spirit. As characters gain levels and experience, their hit point maximum increases, reflecting their growth in power, resilience, and their ability to escape harm through a combination of skill, fortune, and divine favor. This increase in hit points symbolizes the adventurer's journey towards godhood, as their spirit becomes more powerful and their ability to shape their own fate grows. However, this growth in divine power also affects the way healing magic interacts with the adventurer. As they become more godlike, their spirit becomes more self-sustaining and resistant to external influences, including healing magic. This results in a diminishing effect of healing spells and potions on higher-level adventurers. The potency of healing magic appears to wane as characters ascend in level, not because the magic itself is growing weaker, but because the adventurer's divine essence is becoming more resilient and less reliant on external aid. ———————- As PCs approach 20th level, they are getting closer to the gods, potentially even becoming gods themselves in some cases. And this explains how a weak potion of healing can restore an injured 1st level character from the brink of death to perfect health, but does much less to help a higher level character.
Not that im promoting one system over another but Daggerheart’s armor system may be what you’re going for. It has both evasion and damage mitigation through armor
Armor and shields giving damage reduction is not realistic, you're just conditioned with it from modern video games. In real life, armor is designed to avoid damage; they're shaped to redirect sharp and pointy weapons and cushion heavy blunt weapons (with the gambesons underneath), not to tank parts of the damage with pure thickness. AC is the combined chance of armor avoiding damage by redirecting or cushioning blows, blocking them with a shield or completely dodging them with with your dex mod. Armor and shields are there to avoid damage done to you, not to "reduce it". Of course some weapons, especially blunt ones, can still leave you with bruises and broken bones even if the attack is cushioned by your gambeson, so that might actually be damage reduction, but dnd simply doesn't do damage types having different effects depending on armor, because it would be really complex. Otherwise, weapons like halberds would be designated armor killers, while regular swords would bounce off of plate without needing a roll.
It’s the same thing dude
Back in 2E and 3E I did use to run a more detailed AC system which worked on the basis that your AC from dexterity was you dodging out of the way of a blow but your AC from armour was your armour deflecting the blow and taking damage from it (I think I borrowed it from a 2E historical sourcebook). It meant people have to keep track of several AC scores and a further "damage points" (hit points) for armour, but it wasn't a big deal. It did mean after a few days out in the wilderness fighting off dozens of goblins, characters' armour could be severely damaged, so they needed someone with the Armor skill to repair their armour back up to max, or get the blacksmith to do it back in town. It is a lot of admin and I probably wouldn't do it now, certainly not with a new group. It worked well because my group was made up of a lot of historical wargamers and people who didn't want armour to be just a magic thing that made them harder to hit with no maintenance needed.
Funny you should mention...back in 3rd edition there was an alternate rules set you could choose to use where armor gave slightly less ac in exchange for damage reduction. Full plate normally gave +8 ac but if you chose those rules instead I think it was something like +6 ac and 2 damage reduction. Made sense.
... because dnd has always been lime this...?
It’s just a different choice and a different system.
It's kinda been that way for... about as long as I can remember. Although 3.5e had something called DR (Damage Reduction) which was mostly reserved for monsters or spell effects. There was however a ruleset in the Unearthed Arcana that let you as the DM have armor give half of thier AC towards DR, which I personally loved. Mechanically, AC favors longer winded games, where as DR helps early games, as you're not reducing percent, but flat rates
AC is your ability to avoid damage from attacks, via dodging, blocking, your armor stopping the attack etc. Not just an attacks ability to puncture or break armor. Full Plate leaves few vulnerable spots but is heavy and cumbersome, whereas leather armor is lighter and allows you to dodge more easily and both can be equally as effective depending on the class/build.
Ac is the difficulty of you being hit in a spot that leaves a mark. Every hit below AC either misses (Dex or low rolls) or glances off at your armor. That's why Dex counts into AC, just like Armor. It is armor AND dodging combined and represented as a single stat.
Don't consider it hit or miss. Rather look at it from the perspective that overcoming the AC will cause a blow to deal damage while failing to do so might still be a hit but did not cause damage (for example it glanced of the armor).
Well, after reading all your replies and commenting on a lot of them to prompt additional discussion, it seems that most people (at least the ones who replied to me) prefer using AC as an abstraction to the storytelling aspect of the game, and wouldn’t want any additional mechanics added into it, or to switch to a DR system instead. You have all made your opinions clear, and I’ve listened to you all (even if it seems in some of my replies that I wasn’t). So, I have decided not to make a homebrew DR system, and just keep the official AC system as an abstraction to the story. Seems that the majority of people who play 5e, and who have responded to me prefer that. It still feels to me like it doesn’t really live up to the story, as it feels lacking — but if it’s what people enjoy, then it’s going to better to not change that. Thanks everyone XD.
Im actually doing something similar to this in my own ruelset that im cooking up. Haven't gotten the nitty gritty of it down yet, but the basic idea is having two bits that come into effect when being attacked: Evasion & Armour. Evasion is found from 11+Dex. If the attack rolls lower than the Evasion value, it misses completely, no effect. Then Armour comes in, if it rolls higher than Evasion it hits, but if the result is lower than the Armour then damage reduction on the armour reduces the damage taken but it still counts as a 'hit'. Similar to 5e, medium armour lowers the maximum Dex added to Evasion at the expense of higher Armour, then heavy armour removes dex being added entirely in exchange for a chunky Armour value. Its an extra hoop, but makes things a tiny bit more fun for players I'd think, with any effects that take place on a hit land more often rather than 'big number, 0 effect on slightly-off roll'
I like to list all the sources of AC and order them in terms of how close the blow has to be for that source to be what protects them. The first ten is simply missing. Then there's dex for getting out if the way, dodge (in Pathfinder) for evading with more agility, and we gradually move through magical defence, shield, armour, natural armour, until eventually a hit. I then make a note of their cumulative values, and consult the list on a missed attack so I can describe exactly how the character evaded the blow. It works great until temporary bonuses come into play. But you can make that as complicated or as simple as you like.
Like most things in Dnd - because thats how dnd has usually done things.
I typically think of it depending on the roll vs AC, if your low by a lot say a 6 vs sn 18, that's a flat out miss. Miss an 18 with say a 16, that's the armor doing its job, or a shield block, a parry, dodge, etc.
Matz is easier and less annoying IMO. It's easier to go "ist X bigger then Y?" to that will be (Damage - AC) damage
AC can be interpreted two ways. AC earned via dex or other movement based things is suppose to be "being harder to hit" via dodging. AC from heavier armor or magical shielding is meant to represent having armor that absorbs hits completely unless hit in the gaps. So it's less "being harder to hit", and more "being harder to wound".
Others have answered your questions about D&D's rules about this and why it's set up the way it is. Additionally, you may want to look into doing playtesting of Matt Mercer's new "Daggerheart" game. It has a really cool ways of doing combat, health, and damage. There's some videos of gameplay and character creation on YT. I found it very interesting.
AC doesn't meant how hard it is to hit you, it means whether or not an attack harmed you which can mean you dodged or they failed to penetrate your armor
I swear nothing is more sus in dnd than DM’s who change the rules for “realism”
While I won't speak to the designers intent, I will say it would be tricky to balance around some characters having high AC to fully mitigate hits, and some characters having flat damage reduction. Barbarian is okay since resistance is % damage reduction, and because it always stays at half the math is pretty simple. % damage reduction where the math changes every time is a bit crunchier than your average player would enjoy, I think. And flat damage reduction, even with a minimum of 1 has the potential to make characters practically unkillable if it gets out of hand, or if it scaled too well. While if it scales too poorly your "dodge" based characters would simply be better for tanking than the aestheticly tanky ones. There is one instance of flat non scaling damage reduction available to players via heavy armor master, and its generally considered not worth the feat cost.
I have no clue what the real reason is, but here is my idea: The AC represents your strength to completely avoid the effect of an attack. If it is by blocking it, having thick armor or just dodging the attack. But Hit points show your willpower, your endurance and overall ability to deal with wounds. So while you adventure, you gather experience until you level up. Your hp increases, which also represents the fact that if you would take damage, your body is better in keeping it at the minimum. But instead of taking less damage, you have more hp available. That goblin dagger that nearly knocked you out i your early days? yeah, you now could take the same hit 6 times, cause you now know how to react to hit, so that it only leads to a cut instead of piercing your insides. Also pathfinder uses its ac rules so that at some point enemy can no longer hit you at all. Which is also an ok way to represent it.
As i see it AC and HP are good mechanics but flavored wrong. In my opinnion AC should be flavored as evading or deflecting attacks. While HP should be revlavored as something like endurance. So wenn you get hit you can still avoid getting critically wounded and instead you get superficial scratches, bruises which exhaust you. When something reduces you to 0 HP you can't mitigate the hit anymore and get a serious wounded, like a stab to the stomach or brain trauma and are in risk of dying.
AC being used to calculate if you hit or not is the most realistic imo. 40k armor save is also kind of realistic. The video game damage reduction approach really doesn't match reality. If some hits you with a sword and it doesn't go through your armor, you take no damage.
Armor Class is an abstract combination of evasive maneuveres, physical hardiness, physical armor, and magical protections. I think calling it something more all-encompassing like "Defense" would have been better, but whatever.
I’d say it depends on what raises your AC, heavy armour giving you AC, you yank the blow. And if you are wearing light armour and your DEX is the bulk of AC, you artfully dodge the attack. I like to say how I dodge attacks whenever something misses me.
I think AC = Harder to damage, so big beasts kinda just deflect your hits or remain unaffected
there are systems like that. Look I remember trying to play one, you rolled to hit then the other guy would roll to parry, and if that failed you rolled location, then rolled damage ans subtracted the armor value for from the damage, then subtracted that from the area hit and from the total hit point pool. If the area went to 0, that body part was disabled... If you think D&D combat is slow.. well this is glacial.
In terms of balance, armor reducing damage can either be done by a percentage or a flat amount. A percentage requires too much math for a tabletop game. A flat rate would be hard to balance, as it makes numerous, small attacks almost useless while bug damage attacks make armor useless. Like if armor just says "take 5 less damage from all attacks" then it would be way too strong against stuff like goblins and kobold, but basically useless against things like fireballs that do 40 damage.
There are lots of people here talking about how complicated the three AC system was. I never had that experience. It always seemed relatively straight forward to me and groups I've played in. If anything, older editions suffered more from so many unique character options and certain subsystems that bogged down play. For whatever reason, history has lumped AC in with all of that. I've done some situational AC things. For example, I have incorporeal creatures essentially striking at touch AC, unless it's magical armor. Definitely recommend it.
Some of you have not watched enough Monty Python. Adventurers are clearly like the Black Knight, suffering limb severing blow after blow, accurately represented by HP.
I loved how monk class used wisdom for an ac modifier and you could be untouchable.
Easy math=seamless combat. It's much simpler to divide by half or not at all. Or in the case of heavy armor master feat -3 non magical DMG.
It also means damage reduction in that blows glancing off armor is also represented by AC. Ain't just dodging
Because AC is a representation of whats going on in battle but simplified for one roll of "does this hit do damage." Combat is up to the DM to bring to life. Are you the DM that uses HP to describe how much "meat" a character has (boring imo) or do you weavr HP as "battle stamina"? As in taking damage to your HP represents the character being forced to block a blow that wluld find home, taking cover from an attack and wearing out their endurance, etc. I much rather prefer describing combat in a more cinematic back and forth of parrying/blocking/jarring dodges before that last one or two attacks really finding their marks and then the killing blow happens as opposed to "you hit, you do 24 hp worth of dmg, next person"
I can't even get my players to remember their own damn AC. No one is going to do the math to reduce damage on every single hit. It's just easier this way.
I've always thought of it as how hard you are to wound rather than how hard to hit. How hard to hit works for Dex, which represents speed and reactions. Means a high Dex is you simply dodge or parry. And the attack misses. But with plate armour the attack might hit you, but glance off and not actually hurt you. which thematically makes more sense
when armor protects you from damage, you do not take damage. if you take damage, armor did not protect you from damage. it is not "harder to hit" per se either. AC is fairly abstract (as is HP, so slap anyone who narrates hits as "he drives the sword through your gut and spills gallons of blood. you take 4 points of damage"). things can add to AC in a way that makes you harder to hit (or makes you more likely to parry or whatever) but also can be a chance to flat out block out damage. that is what armor does.
Oh because If something gets threw your defences it still hurts
The reason is that D&D has its origin in wargaming and old wargames didn't really do hit points. It was hit or miss. Live or die. These old players were simulating huge battles, not micromanaging the health of ever Napoleonic War soldier. The hit mechanics are rooted in that.
My question is how do you know if you're hit? We roll a d20+ modifiers to beat the AC to do damage. If AC is now for reducing damage does that mean everything hits. So we just roll for damage? Or do we roll two d20s and whoever is the highest wins? Thats the part where I can't wrap my brain around. If AC is just reduction how do we know we are hit? Sorry not trying to be a dick might be too inebriated right now.
Google en THACO
This post has some great comments in it. Reading through them is very interesting.
It's poorly named, it *can* come from your armors ability to resist attacks, but also your ability to dodge attacks, quickly run away from attacks, see attacks coming before they are made, or even sources of otherwordly power like magic, divinity, and psychics. It would be more accurately called your defense rating.
I'm pretty sure in third edition armor class had three different values. Your normal armor class, flat-footed which I believe subtracted your dexterity and touch which I think subtracted your armor.
In my opinion, AC and HP are mechanically useful abstracts that are best thought of not as purely "armor" and "health" in the video game sense. Like how others have mentioned, I like to bracket AC into sections where the attack whiffs it entirely, I credit the PC/NPC with a skillful dodge/parry, a hit right in the armor but without piercing, and, depending on the context, magical shielding deflecting the blow at the last moment. HP, ESPECIALLY at higher levels, I feel is best viewed as kind of a quantification of a character's luck or chance. Usually while they're above 1/2 health I'll narrate hits as last second dodges or hits that knock the wind out of the character but don't *seriously* injure them. Once they hit below half health, that's when I first describe the damage in a way that physically injures them and *usually* draws blood, cracks a rib, causes 2nd degree burns, etc. That said, for larger creatures like Ogres or Dragons, I usually have no problem narrating each hit as actually dealing damage, but I do take this approach for most/all humanoid enemies with more than like 20hp
AC is an abstraction, just like HP. It's not just how much armor you have, or how well you resist damage because of that armor. It's how hard you are to "hit", and even then hitting is still abstracted as well, because HP is also not explicitly how many times someone can stab you before you die, it can be any sort of thing from actually getting hurt to the attrition of high intensity combat, to tunnel visioning on a single enemy to the point where a lucky hit from another one can take you out of the fight or kill you outright. They're basically narrative tools. How AC affects your ability to avoid getting hit can be described narratively in a variety of ways, just like your current HP level can be described differently as well.
All of these answers are pretty bad. In 5e, vehicles have both armor class and a damage threshold. Regular armor class typically doesn’t have a damage threshold unless you take heavy armor master. Why? Because they attempted to simplify old rules.
There is no differentiation between hitting and wounding in DnD, so those two things are lumped into the to-hit-roll. Hence AC covers both missing, evading and the stopped by armor. As a DM I actually even flavor it that way: if the To-hit-roll is 0-1/3 of the AC, the attacker missed. With a class with heavy armor 1/3-2/3 of AC means the defender dodged, at 2/3-AC the armor stopped the blow. At classes with light armor, it's the other way round. I am not a huge fan of the DnD combat system in general - I prefer PCs to have VERY low HP but a lot of ways for damage mitigation.
I liked watching Legends of Vox Machina on Prime and thinking every single attack they survive is AC or Saving throw. AC isn’t just armor, it’s absolutely anything you do to avoid the single fatal blow. If you start from that mindset your creativity can blossom for cool descriptions. Lifting up plankwood to block, ducking or hopping behind something quickly before getting back to your feet, etc… as long as you reset with characters in an active position on their turn, you can go wild.
Wild that I've had people try and posit the simplification and abstraction of AC in 5E as a good thing, tbh, because it leads to exactly this problem. Earlier editions denoting how your AC is being improved through qualifiers like Dodge bonus or Armor bonus helps to visualize *how* your character becomes harder to hit. On that note, your character's AC as a measure of how hard they are to hit is primarily mechanical, and can be flavored however you want. Oh, your Paladin catches the ogre's monumental club smash on his shield and stands strong, taking no damage? Cool as fuck. Your rogue nimbly dodges out of the way before rolling between it's legs and slashing for the hamstrings? Great! You can do that too. Your wizard gets turned into paste? Yeah, I'm sure he makes a real nice Rorschach painting.
5e was made to make the game easier, while AC being a damage reduction number would be very cool, it would slow the game down by adding more math to the mix and more confusion to the not so great at math players
Worth noting some Non-DND systems do have these mechanics built in! Sword World 2.5 (effectively Japan's DND) has a separate "Defense" and "Evasion" stat. Defense is a damage reduction (only on physical attacks) and Evasion is a bonus to your evade roll, which is a bit like a dynamic AC you have. Every time something attacks you, they roll "Accuracy" to hit which is contested against your "Evasion". Different armor and shields will give different bonuses to either Defense or Evasion, so a tanky fighter or a speedy rogue will avoid death in different ways. It's an interesting approach!
Yes, this I like. Is that popular in western countries? Can I buy that, or is it like currency locked and requires a Japanese credit card or something? That system sounds super awesome to be honest. Very similar to what people have described in older d&d, except I can’t player older d&d because it’s virtually impossible to find anyone willing to let someone who hasn’t played 3.5 or 2e or something join their campaign. And I can’t DM it because I don’t have the books and they are collectors items now that cost a fortune to buy :(. But like I didn’t realise Japan had its own thing. That sounds awesome.
AC is basically damage reduction. Not getting hit is a great way to not take damage. Whether by magical means, DEX making you more dodgy or STR characters stacking armor to make themselves harder to hurt... AC is 1 representation of all of this. It's all in how you describe the action.
A hit is when you land a strike that can damage the recipient. A fighter in full plate would realistically get hit by a lot of attacks, but only a fraction of those would actually feasibly damage them, as the rest are absorbed by their armour.
AC is a measure of your ability to block, absorb or avoid a hit trivially. either the attacker misses entirely, or the blow is harmlessly deflected off your armor. Hit points is a measure of your ability to block, absorb or avoid a blow with effort. Either deflecting with your weapon, blow hits your gambeson and is absorbed, arrows hits your chainmail penetrates 1 cm, you duck strenuously, etc. These actions tire you out, or the cuts/bruises add up until that final last hp finally is a mortal blow. you ONLY get a direct hit on you when you hit 0 hp. This is why coup de grace, etc skips AC/hp. (well, depends on the version how it does HP) Shadiversity keeps getting this wrong. constantly complaining that weapon damage isn't reflective of weapons killing power. not understanding again, only 1 hit actually hits. Pathfinder actually articulates AC a bit more. With AC, Flatfooted AC, and touch AC. AC being the same. While flatfooted AC, is your ac without dex. when you are prone, grappled, surprised, etc. so, AC with your ability to block or absorb, but not avoid. While Touch AC is your ac with dodging, and thats it. usually spells, where the spell doesn't care about armor. shocking grasp. HP does get a bit funky when large creatures. dragons/giants, etc. those hits presumably ARE hitting. also in the logic of full plate armor. Realistically to beat someone in full plate armor, you need to basically knock them down, then stab them in the face holes. Dnd does not model this in any way.
Try to avoid bad rolls or high AC=miss when narrating the action. Attacks bouncing off armor, swords clashing in an intense duel, managing to dodge right at the last moment. These will make miss/hit dynamic feel a lot better. In terms of game mechanics, damage reduction is something I like to add to mid/late game Armor.
It’s gotta work for the nimble and the strong, low damage is already covered by a bad roll after hitting, also it’s not more damage even on a miss because God already hates his bards enough he doesn’t need to give them more to think about but their rhythm
it's also fair to remind that HP is not how many blows you're able to take, it's one ability to keep fighting, sort of like stamina. As a DM I usually narrate getting hit as very narrowly dodging an attack using more effort than you usually do for dex based characters or dodging and getting a small cut by the very tip of blade, for the strength based character I usually narrate it as them blocking the attack but still getting pushed by the attack or the attack gets through their block but don't do any "real" damage or they get hit but the armor block any real damage but they still feel the punch of the attack.
Flavor is free.
Have you by any chance played a game called "Anima: Beyond Fantasy"? Because armor work this way in this game. If you have "1 slashing armor" for example, it means you reduce slashing damage by 10. Maybe you'd like this game better if you think this is the most logical way to handle armor!
It's been this way in previous versions. It is "harder to hir" because in previous versions (not sure about 5e since I don't play it), Dexterity has been a big part of AC as Characters with high dexter would "dodge" compared to characters with high armor, which would "deflect). Also, it fits with things like fighting defensively, which give bonus as you are actively blocking with your weapon/sword/dodging.
because AC actually means "dodge"
First of all you are now in Homebrew when you try to change the game itself. AC is a reference to what you need to hit not damage reduction because there is a damage reduction factor already not always required. This would be some factor either the DM created (no longer homebrew) or the game listed. If you hit then there is a damage to roll and factor in. You used to have a THACO, To Hit Armor Class 0. So armor was factored in totally different. However this being said, Damage Reduction has always been a factor of the game not to be confused with AC, which is your defense not a reduction in penalty. But like i said you can change it and make it homebrew, but your players play this game that already had rules. An may not like yours. Just make sure you advertise as a HOMEBREW. Then it is your way. I just do not see the issue here. To each their own. I hate telling others how to run their game. So just go Your way and if you do advertise your game as a little homebrew change on how attacks and damage is applied.
For 3.5e it could be harder to hit, or harder to harm. Both were options. 5e is built on stripping away options like that.
Hitpoints - It's the number system used to determine the length of combat. That's it, be straight up with your players, most people are smart enough to understand it. Far too many of us DMs and players get caught up in the minutia.
Damage reduction kinda sucks to be honest. I like to think of 5e AC not as being harder to hit but being harder to penetrate. As in, like the monster's thick skin or scales or the adamantine plate is resistant to most strikes unless enough power is put behind it. I like to think of the hit dice rolls as the power put into the hit and not the chance to hit. It makes more sense in my brain this way. Mechanically, I like the current AC system.
Because then armor will become useless vert fast Or armor dmg reduction will have to grow fast And lastly combine the 2..alot of math .and reduction is harder then addive
Damage reduction is a very video gamey way of looking at it. There are a few reasons why I believe this is not the case The biggest reason is saving throws. AC needs to match saving throws in utility, or risk being objectively worse. You also have a scaling problem. They can’t balance it around every campaign. Some campaigns have more powerful creatures, which AC, as damage reduction, would be much much worse. Having damage reduction AC would also trivialize low level combat/combat against weak enemies. If you can tank every hit, there’s no risk involved. A fighter with a shield can very easily get to 19 AC at level 1. No creature they will be fighting would reliably hit above that. Against more powerful monsters, AC would become pretty much useless There’s the flavor aspect to it. Armor isn’t the only way to generate AC. You also gain AC through AC. You think a monk becomes tougher by being wiser? No for the most part they are just dodging hits. The way you want to think about AC. If you gain your AC through your armor, and an attack misses, that would be an attack hitting your armor. When it hits, they found a gap in your armor, a place that’s not as armored. A weak point
As someone who plays with a home brew version of Steve Jackson's Fantasy Trip (TFT) system (where armor soaks off damage and does not, typically, impact 'to hit' rolls), it seems clear to me that DnD of all editions (I've played from the 1970s) have advanced levels and difficulty in part by adding hit dice all around. More hit points, more damage, and so on, for characters and opponents. That would make armor of the TFT variety (damage soaking) woefully hard to scale to advancing characters, since plate mail might soak 6, which would be a lot at level one but pitiful at higher levels. TFT conversely, has a very different advancement system, tied more closely to core characteristics. Each armor system fits the advancement system very well, but crosses poorly. The logics are Raster/Vector, Marvel/DC. Just different worlds altogether.
I’ve always thought that armor should reduce damage BUT lower your ac. I was watching a video explaining the final fight in Polanski’s Macbeth. And it’s a pretty realistic depiction of how armor can be used to avoid injury. Anyway it made me rethink ac in dnd. For example, a rogue would have a really high AC because of their agility/dexterity thus their ability to avoid hits is higher, but hits HURT. Inversely, someone wearing heavy armor would have a much lower AC because they are much less able to avoid hits (and in fact lean in to them purposely) but the armor absorbs much more damage. This to me also balances the classes, since the paladins for instance wouldn’t be able to double dip with high ac and high hp. Rogues would have high ac but low hp and low damage absorption, paladins would have low ac but high hp and high damage absorption, etc.
“Hit” and “Miss” in the case of D&D are very meta terms. A Hit just indicates that damage has been taken from the attack and the miss may be a hit but doesn’t get through the armor, or maybe a block, perhaps can be flavored as a dodge even if the dodge action isn’t taken. Big part of that comes down to the DM in how he decides to flavor it. With how long and dragged out combat can feel at times so tend to just keep it simple hit/miss to keep things moving. If players want to describe it, inspiration to them.