I'm currently writing a skill-based game, and one of my major goals for it is to keep the rules very, very simple.  As such, I started with the simplest system for skill advancement I could think of:  1 xp buys 1 point of advancement in a skill.  There's a bit more to it, but that's sufficient context for my question.  I have various concerns, they greatest of which is incentivizing over-specialization, but if it's worked okay in other games I might leave it as it is.  I'm also concerned that it might cause issues that I haven't anticipated.

So, then, what has your experience been in playing such a system?  What problems, if any, did it cause? 

I think it was an older version of Runequest where if a character used a skill during an adventure, they put a checkmark by that skill. At the end of the session, the player would do a test for that skill to see if it increased. If your system is skill based, have you considered a similar system?

Seeing you're using xp, I used to do the After X sessions, get a level, but grew very dissapointed with that type of system and abandoned it. I like an xp system to have enough granularity to be able to use individual awards. I like giving out bonus xp, and xp for individual characters. That requires an xp system with large enough values to accomadate such awards.

My experience with such systems is that linear cost increases are too little and exponential increases are too much.  Except for some niche cases where there really isn't much growth in skills at all (for whatever reason), in which cases it doesn't matter much how you do it.  You really need something like a Fibonacci sequence (1, 2, 3, 5, 8, 13, 21, ...) or a Log sequence (roughly x1.4 on previous value) for the underlying math, then flattened and rounded a little into more friendly numbers.

1 xp increments for everything can get very tricky, fast, but that doesn't mean the numbers need to be huge.  Even 5 or 10 xp as the base increment gives you a lot of room, working backwards into the cheapest thing being 1 xp.  If that works out such that it applies to a lot of skills, most of the time, then great, but don't force it.

Moreover, over-specialization is often (but not always) better handled by careful selection of the scope of the skills, rather than monkeying with the cost of them.  For example, if you don't want there to be a "face" guy in the party every time, then make sure to have more than one "social" skill.  But if you want some subset of the characters to be notably capable of "face" interactions, then don't have too many "social" skills, either.  Of course, this starts to have repercussions in how you break down skills across the board.  For that reason, the simpler the system, the more carefully the skills need to be selected, scoped, named, etc.

If something is significantly off this pattern but everything else is working, then consider strongly moving that something else out of the skill system.  Yes, it makes the game a little more complicated that you've got these special case widgets, but not as complicated as trying to shoehorn them into an otherwise working skill system.  For example, this is  why in my current system "perception" became an attribute instead o a skill.  (Well, a major reason out of several.)  It's also why I've got a separate category of "knacks" that are like broad skills, with a relatively short list, that stacks with skills.  The knacks being broad helps a lot with over-specialization, too, which was important to me given the nature of the game expected more generalist characters.

Quote from: Mishihari on March 10, 2022, 05:51:36 AM
I'm currently writing a skill-based game, and one of my major goals for it is to keep the rules very, very simple.  As such, I started with the simplest system for skill advancement I could think of:  1 xp buys 1 point of advancement in a skill.  There's a bit more to it, but that's sufficient context for my question.  I have various concerns, they greatest of which is incentivizing over-specialization, but if it's worked okay in other games I might leave it as it is.  I'm also concerned that it might cause issues that I haven't anticipated.

So, then, what has your experience been in playing such a system?  What problems, if any, did it cause?

I don't understand your question very well, perhaps it's my English that sucks, but what exactly are you trying to accomplish?

A simplistic experience system could be Godbound's. It works as follow:

QuoteA session's XP award starts at one point, for the players simply showing up and playing. The GM adds another point if they successfully obtained a situation's draw or dealt with its threat, what the PCs might recognize as having "succeeded" at the evening's adventure. A third point is awarded if the PCs were engaging a challenge that was a serious test of their abilities, opposing an enemy or situation that was perhaps beyond them, whether or not they successfully overcame it.

But you don't just have to reach an ever growing quantity of Experience points to level up, you must also spend Dominion to change the world around your character to grow in power. What do you think?

Pathfinder 2E went to a very curious system where you always gain a level at 1000 xp. To balance this, battles between enemies at your level yield more XP than battles against lower-level enemies.

Quote from: Ratman_tf on March 10, 2022, 06:05:11 AM
I think it was an older version of Runequest where if a character used a skill during an adventure, they put a checkmark by that skill. At the end of the session, the player would do a test for that skill to see if it increased. If your system is skill based, have you considered a similar system?

The system from Torchbearer/Mouse Guard and such is quite elegant as well. To gain a higher rank in a skill, you have to pass a number of skill checks in that skill equal to its current rating, and fail a number of checks equal to one less than the current rating.

Quote from: Trinculoisdead on March 10, 2022, 10:00:55 AM

Quote from: Ratman_tf on March 10, 2022, 06:05:11 AM
I think it was an older version of Runequest where if a character used a skill during an adventure, they put a checkmark by that skill. At the end of the session, the player would do a test for that skill to see if it increased. If your system is skill based, have you considered a similar system?

The system from Torchbearer/Mouse Guard and such is quite elegant as well. To gain a higher rank in a skill, you have to pass a number of skill checks in that skill equal to its current rating, and fail a number of checks equal to one less than the current rating.

That's pretty clever. The required failures mean you're testing your skill against tasks that are difficult enough to be failed. You can't just churn out a dozen horseshoes every time you want to advance as a blacksmith; you have to try your hand at more difficult tasks in order to actually advance. It also factors in that people often learn as much from failure as from success.

That said, it only works for a subset of skills... as the saying goes; "if at first you don't succeed, skydiving isn't for you."

Quote from: Chris24601 on March 10, 2022, 11:54:12 AM
That said, it only works for a subset of skills... as the saying goes; "if at first you don't succeed, skydiving isn't for you."

Whether this is true or not entirely depends on the scope and granularity of skills. If the skill is "Jumping," the requisite failures don't necessarily have to be "... out of an airplane."

Quote from: Ghostmaker on March 10, 2022, 08:29:43 AM
Pathfinder 2E went to a very curious system where you always gain a level at 1000 xp. To balance this, battles between enemies at your level yield more XP than battles against lower-level enemies.

I remember one d20 house rule dispensed with XP and said "you gain a level after 13 encounters." I think it also changed encounters to "tokens," which could be gained for events other than violent encounters.

Quote from: BlazingPolyhedron on March 10, 2022, 08:01:56 AM

Quote from: Mishihari on March 10, 2022, 05:51:36 AM
I'm currently writing a skill-based game, and one of my major goals for it is to keep the rules very, very simple.  As such, I started with the simplest system for skill advancement I could think of:  1 xp buys 1 point of advancement in a skill.  There's a bit more to it, but that's sufficient context for my question.  I have various concerns, they greatest of which is incentivizing over-specialization, but if it's worked okay in other games I might leave it as it is.  I'm also concerned that it might cause issues that I haven't anticipated.

So, then, what has your experience been in playing such a system?  What problems, if any, did it cause?

I don't understand your question very well, perhaps it's my English that sucks, but what exactly are you trying to accomplish?

A simplistic experience system could be Godbound's. It works as follow:

QuoteA session's XP award starts at one point, for the players simply showing up and playing. The GM adds another point if they successfully obtained a situation's draw or dealt with its threat, what the PCs might recognize as having "succeeded" at the evening's adventure. A third point is awarded if the PCs were engaging a challenge that was a serious test of their abilities, opposing an enemy or situation that was perhaps beyond them, whether or not they successfully overcame it.

But you don't just have to reach an ever growing quantity of Experience points to level up, you must also spend Dominion to change the world around your character to grow in power. What do you think?

I'm specifically asking about a way of converting experience points to skill advancement.  All replies are appreciated, as they may spark ideas for me to work with, but I'm hoping that a few folks have tried the approach I describe and can tell me about any pitfalls they've encountered.

Quote from: Steven Mitchell on March 10, 2022, 07:47:07 AM
My experience with such systems is that linear cost increases are too little and exponential increases are too much.  Except for some niche cases where there really isn't much growth in skills at all (for whatever reason), in which cases it doesn't matter much how you do it.  You really need something like a Fibonacci sequence (1, 2, 3, 5, 8, 13, 21, ...) or a Log sequence (roughly x1.4 on previous value) for the underlying math, then flattened and rounded a little into more friendly numbers.

1 xp increments for everything can get very tricky, fast, but that doesn't mean the numbers need to be huge.  Even 5 or 10 xp as the base increment gives you a lot of room, working backwards into the cheapest thing being 1 xp.  If that works out such that it applies to a lot of skills, most of the time, then great, but don't force it.

Moreover, over-specialization is often (but not always) better handled by careful selection of the scope of the skills, rather than monkeying with the cost of them.  For example, if you don't want there to be a "face" guy in the party every time, then make sure to have more than one "social" skill.  But if you want some subset of the characters to be notably capable of "face" interactions, then don't have too many "social" skills, either.  Of course, this starts to have repercussions in how you break down skills across the board.  For that reason, the simpler the system, the more carefully the skills need to be selected, scoped, named, etc.

If something is significantly off this pattern but everything else is working, then consider strongly moving that something else out of the skill system.  Yes, it makes the game a little more complicated that you've got these special case widgets, but not as complicated as trying to shoehorn them into an otherwise working skill system.  For example, this is  why in my current system "perception" became an attribute instead o a skill.  (Well, a major reason out of several.)  It's also why I've got a separate category of "knacks" that are like broad skills, with a relatively short list, that stacks with skills.  The knacks being broad helps a lot with over-specialization, too, which was important to me given the nature of the game expected more generalist characters.

Thanks for the insight, definitely food for thought. 

My fallback is to have each skill advancement cost experience equal to the new skill level, frex going from climbing 2 to climbing 3 costs 3 experience.  This gives polynomial progression, as the total experience required to achieve a skill level of n is 1/2 n^2 + n/2.  This has the advantage of not requiring a table or formula, but it's still more complicated than I would like.  The game is aimed at people who've never played an RPG before, so I want to keep the complexity as low as possible, since it's a barrier to entry.

One of the complicating factors is that experience is used to buy more than skills.  It's also used to buy talents (think ability scores), resilience, fortune, and a few other things, which works pretty well already.  If I switch the scheme for buying skill points, I'll need to alter the rest as well.

Quote from: Mishihari on March 11, 2022, 02:25:05 AM


My fallback is to have each skill advancement cost experience equal to the new skill level, frex going from climbing 2 to climbing 3 costs 3 experience.  This gives polynomial progression, as the total experience required to achieve a skill level of n is 1/2 n^2 + n/2.  This has the advantage of not requiring a table or formula, but it's still more complicated than I would like.  The game is aimed at people who've never played an RPG before, so I want to keep the complexity as low as possible, since it's a barrier to entry.

One of the complicating factors is that experience is used to buy more than skills.  It's also used to buy talents (think ability scores), resilience, fortune, and a few other things, which works pretty well already.  If I switch the scheme for buying skill points, I'll need to alter the rest as well.

Not saying that it can't work, but am saying that I've tried several times and not liked the side effects.  Specifically, what I had to do to squash things into the pattern caused more trouble than using other, seemingly more complicated, means.  I've got a lot of casual players too.

For something like 1 XP for 1 point increase versus XP equal to the current rank of the skill for 1 point increase, not really much difference between them.  If the edge case at start really bothers you, you can say "XP equal to the new rank of the skill", i.e. go from zero to 1 rank is 1 point.  That causes a very short stop in casual players while they think about it, then it's good.  The main side effect is when you build characters at start that have higher skills, which is when you need a chart for them to use.  It's a little more aggravating on character audits, too, but that's on the GM.  (I tend to do those because I find most casual players are constantly cheating themselves out of something they are supposed to have.)

You can also stick to "XP equal to the current rank of the skill" and simply hand-wave the 1 skill point.  If it's a starting character and you have the skill, you have it.  If it's an existing character in the campaign, they start learning the skill as part of role play or downtime, and then they have it when the GM says they have it.  No points needed.   Which has its own pros and cons.

That's all aside from what the expected ranges of skills are.  Once you take that into consideration, then you can often end up with something like this, that works close enough:  Let's say that negligible, still learning skill level is 1 to 2, standard in the campaign is 3 to 8, and really talented is 9+.  You can use a gradual formula to approximate that, or you can just soft cap it.  Starting skills costs 1 XP per +1 rank.  When the skill gets to 2, it costs 3 XP per +1 rank.  When the skill gets to 8, it costs 5 XP per +1 rank.  In such a system, you've probably got a hard cap somewhere above that, too.  Sounds complicated, right?  But most skills that most characters care about are already 2+ in the starting character generation, and most characters have very few, if any, skills at 9+.  Net effect, most of the time increasing a skill cost 3 XP per +1 rank. 

Now, it might turn out that the edge case at the bottom is not worth having a difference.  Give them more points to start and just make the skills 3 XP per +1 rank up to 8.  Might be a good choice.  Note, however, that the other way has a subtle nudge against specialization that you've just lost.  Not a lot, but it is there.  Likewise, you might decide instead of 5 XP on the upper soft cap, just make it double, at 6 XP.  Easy to remember.  That's a subtle nudge towards making your soft cap a little harder.  Might be good or bad, depending on what you want to accomplish. 

My main point, is that such decisions should be driven by the nudges more than dredging out that last little big of simplicity.  You want it as simple as you can get, but no simpler.  If you can get 80% of simplicity with soft caps as opposed to the polynomial progression, from the standard player's perspective, while keeping 80% of the effects of the progression, it might be worth doing.  It's much more important to limit the number of such systems than it is to use any one in particular.  However it works, buying other things should be as much like it as possible, unless there is a strong reason why not.  If attributes can be bought, and skill use soft caps, then attributes should probably use soft caps, though the caps might be different.  If skills use polynomial progression, then attributes should too, though the starting cost and escalating amount will be more. 

Quote from: Mishihari on March 10, 2022, 05:51:36 AM
I'm currently writing a skill-based game, and one of my major goals for it is to keep the rules very, very simple.  As such, I started with the simplest system for skill advancement I could think of:  1 xp buys 1 point of advancement in a skill.  There's a bit more to it, but that's sufficient context for my question.  I have various concerns, they greatest of which is incentivizing over-specialization, but if it's worked okay in other games I might leave it as it is.  I'm also concerned that it might cause issues that I haven't anticipated.

So, then, what has your experience been in playing such a system?  What problems, if any, did it cause?

I prefer adding a point to a skill when going up a level.

Can't remember is this is the default RAW, but when we played Star Wars d6 we played that any time you used a skill for something difficult, you put a check next to it.  At the end of the session, you could raise one skill one die level increment. 

In this system to attempt a check, you roll a # of d6, sum them, and try to meet or beat a target. 

Thus you could raise a 3D skill to 3D+1.  Then to 3d+2, then to 4D, etc.  There a whole mess of skills so it worked out pretty well.

Quote from: Ghostmaker on March 10, 2022, 08:29:43 AM
Pathfinder 2E went to a very curious system where you always gain a level at 1000 xp. To balance this, battles between enemies at your level yield more XP than battles against lower-level enemies.

I changed the xp system to a % based by cutting the xp to a 10th.   160 xp encounter would be worth 16% instead.   Not sure why they didn't go that route.   It worked out quite well at our table.