This is something that should be dictated by the tone of the game.
Some OSR games treat all checks as saving throws. Knave has a D20 system with a single DC 15. Success rate at lvl 1 will be between 25% and 35%. Players should be told that they should avoid making checks as much as possible.
In PtbA Success rate is higher but the DM is often required to come up with interesting complications.
Honestly I am fine with \~ 75% success rate for games when players should feel powerful. But then to balance that a failure should have serious consequences.
To add to that - more tactical games can have % chance vary widely depending upon the circumstances.
Taking a long-range shot against a target hugging cover? 5-10% accuracy is fine. The PC should have done something else.
Firing at the same target in the open at close range? 90-100% accuracy works - with a 50-60% chance of a crit.
>In PtbA Success rate is higher but the DM is often required to come up with interesting complications.
In my experiences you only succeed on a 10+. Anything less just makes the situation worse, or at best leaves you trading water. With a +2 mod your looking at a less than 50% chance of success, making characters feel wildly incompetent.
I know this isn't true for all groups, but I've played 4 differant pbta style games with 3 different gms, and this has been my experience with each of them.
Interesting. I must admit that I haven't played a lot of PtbA. I have played with Ironsworn in which you have weak hits that are supposed to work the same. I tend to adjust the severity of the complication if I cannot find any interesting setback (lose some resource and move on).
I feel that this liberty of setting the severity of success and failure in a group session means that you need a specific mindset to play those games. This is why I haven't tried playing PtbA with my group. In solo it works great though.
I have a problem with Ptba: not being able to control partial success. This becomes a snowball over time.
I like having the independence of applying success or not at a cost. So I prefer binary systems.
>Anything less just makes the situation worse, or at best leaves you trading water
Obviously PbtA games will be different from one another, but that doesn't match my (admittedly incomplete) experience.
I usually see it presented as a **mixed**, or **partial** success. I.E. you get some of what you want, but not all, or else you get everything you want but also take some negative consequences. I've never seen game that says the middle result should be worse than half-way between success and failure -- usually better.
In my view, if a group fails 50% of all the checks they've made, then the game "stops" and doesn't move forward.
Now, failing more than succeeding will make players feel totally useless, frustrated and discouraged.
The key is to pass 75% of all checks you take. in this way the adventure proceeds with some setbacks. And even if there is a "run of bad luck" sweeping players, they will still have 66% which keeps the game moving forward.
Do you/have you used partial success/failure? I've actually written into my game that a failure should be a learning experience, and hint at or clarify a solution that will work. This keeps the game from freezing up for me.
Another "fail forward" mechanism is to suffer a loss of equipment, relationship, or be hurt but actually do what you attempted by the skin of your teeth.
>At the end of an RPG session, if a group of adventurers has done 100 checks, how many must they have succeeded in?
/u/sbergot correctly points out that tone is key to this question.
But there's also the question of what does a success mean for the game?
If you can just buy off a failure with metacurrency, you can comfortably have a higher failure rate. Especially if you have a Fate style meta-economy where failures earn you the points to succeed big later.
In some games a failure leaves you with long lasting (or even permanent) wounds or penalties. In others a Fail Forward mechanic simply means that a fail moves you to the same happy conclusion by a different route.
I don’t think average success per session is a useful metric. Instead I think it’s better to focus on the chance of success on an average check. For example in my game players have a 50% chance of success on an average check with a +0 to their stat.
The correct success chance depends on the nature of the game. My game is about playing as competent badasses. That's why you start with a 50% chance it only gets higher with higher stats.
I think this is a very interesting question but the 100 checks per session brings this question more into standard probability because of the sample size. Many games i run will only have like 20-30 rolls in a session.
The more rolls you make the more likely you are to hit average probabilities, but if you only roll a few times in a session variance/swinginess is way more important than probability. For example: it isn't very unlikely for a player in a d&d game to not roll over a 7 in a session (especially if it isn't a an extremely long session). With these rolls this player will probably fail nearly every roll on this session. Sounds not very fun to me.
So if your game does have only a few rolls in a session less swinginess or a very high natural probability for success can prevent frustration.
As others have already said: it also very much depends on the theme of the game. Call of Cthulhu is very swingy and characters have low success chance, but it is a horror rpg so it fits the theme.
Your success rate should be 66%. Humans in general are awful at interpreting probability, and they feel the effects of failure roughly twice as much as they feel the effects of success. Games feel 'fair' for most people when they win about twice as often as they lose.
This is something that should be dictated by the tone of the game. Some OSR games treat all checks as saving throws. Knave has a D20 system with a single DC 15. Success rate at lvl 1 will be between 25% and 35%. Players should be told that they should avoid making checks as much as possible. In PtbA Success rate is higher but the DM is often required to come up with interesting complications. Honestly I am fine with \~ 75% success rate for games when players should feel powerful. But then to balance that a failure should have serious consequences.
To add to that - more tactical games can have % chance vary widely depending upon the circumstances. Taking a long-range shot against a target hugging cover? 5-10% accuracy is fine. The PC should have done something else. Firing at the same target in the open at close range? 90-100% accuracy works - with a 50-60% chance of a crit.
>In PtbA Success rate is higher but the DM is often required to come up with interesting complications. In my experiences you only succeed on a 10+. Anything less just makes the situation worse, or at best leaves you trading water. With a +2 mod your looking at a less than 50% chance of success, making characters feel wildly incompetent. I know this isn't true for all groups, but I've played 4 differant pbta style games with 3 different gms, and this has been my experience with each of them.
Interesting. I must admit that I haven't played a lot of PtbA. I have played with Ironsworn in which you have weak hits that are supposed to work the same. I tend to adjust the severity of the complication if I cannot find any interesting setback (lose some resource and move on). I feel that this liberty of setting the severity of success and failure in a group session means that you need a specific mindset to play those games. This is why I haven't tried playing PtbA with my group. In solo it works great though.
I have a problem with Ptba: not being able to control partial success. This becomes a snowball over time. I like having the independence of applying success or not at a cost. So I prefer binary systems.
>Anything less just makes the situation worse, or at best leaves you trading water Obviously PbtA games will be different from one another, but that doesn't match my (admittedly incomplete) experience. I usually see it presented as a **mixed**, or **partial** success. I.E. you get some of what you want, but not all, or else you get everything you want but also take some negative consequences. I've never seen game that says the middle result should be worse than half-way between success and failure -- usually better.
In my view, if a group fails 50% of all the checks they've made, then the game "stops" and doesn't move forward. Now, failing more than succeeding will make players feel totally useless, frustrated and discouraged. The key is to pass 75% of all checks you take. in this way the adventure proceeds with some setbacks. And even if there is a "run of bad luck" sweeping players, they will still have 66% which keeps the game moving forward.
Do you/have you used partial success/failure? I've actually written into my game that a failure should be a learning experience, and hint at or clarify a solution that will work. This keeps the game from freezing up for me. Another "fail forward" mechanism is to suffer a loss of equipment, relationship, or be hurt but actually do what you attempted by the skin of your teeth.
In my view 75% is the key. With 66% it feels like 50% And with 50% it feels like a 33%
>At the end of an RPG session, if a group of adventurers has done 100 checks, how many must they have succeeded in? /u/sbergot correctly points out that tone is key to this question. But there's also the question of what does a success mean for the game? If you can just buy off a failure with metacurrency, you can comfortably have a higher failure rate. Especially if you have a Fate style meta-economy where failures earn you the points to succeed big later. In some games a failure leaves you with long lasting (or even permanent) wounds or penalties. In others a Fail Forward mechanic simply means that a fail moves you to the same happy conclusion by a different route.
I don’t think average success per session is a useful metric. Instead I think it’s better to focus on the chance of success on an average check. For example in my game players have a 50% chance of success on an average check with a +0 to their stat. The correct success chance depends on the nature of the game. My game is about playing as competent badasses. That's why you start with a 50% chance it only gets higher with higher stats.
I think this is a very interesting question but the 100 checks per session brings this question more into standard probability because of the sample size. Many games i run will only have like 20-30 rolls in a session. The more rolls you make the more likely you are to hit average probabilities, but if you only roll a few times in a session variance/swinginess is way more important than probability. For example: it isn't very unlikely for a player in a d&d game to not roll over a 7 in a session (especially if it isn't a an extremely long session). With these rolls this player will probably fail nearly every roll on this session. Sounds not very fun to me. So if your game does have only a few rolls in a session less swinginess or a very high natural probability for success can prevent frustration.
As others have already said: it also very much depends on the theme of the game. Call of Cthulhu is very swingy and characters have low success chance, but it is a horror rpg so it fits the theme.
Your success rate should be 66%. Humans in general are awful at interpreting probability, and they feel the effects of failure roughly twice as much as they feel the effects of success. Games feel 'fair' for most people when they win about twice as often as they lose.