1 Point = +1 Skill Level works well if you're going with a level-based system where character progression is handled through Character Level (CL) and characters get a couple of points every time they advance to build up their abilities, perhaps with a skill cap based on current CL. That way skills can never go beyond a certain point and how often or much you can improve your abilities is limited by your ability to keep leveling your character. And it can also be mitigated by increased XP requirements to improve your CL, or reduced XP gains based on your current CL, as PF2 handles it (mentioned in Ghostmaker's post). That way higher CL characters have a harder time continuing to improve their skill, while keeping skill costs simple. Though, that also means that skill improvements also stop after a certain point if you have CL caps, or it may become prohibitive to learn new skills if progression slows down too much at higher CLs.

But in straight skill-based systems without CLs that might become an issue as Steven Mitchell laid out. 1 XP = +1 Skill Level means characters might be able to cap out their skills too quickly and depending on how many skills there are, maxing out every skill might become too easy.

XP Cost = Skill Rank is fairly easy to remember, though. The biggest issue is character creation, where players need to budget their starting points and calculate individual cost per skill level. Even if you include a table with total XP costs per level (recommended if going this route) that still means players have to account for different costs per skill level when distributing their starting points, which will make things more difficult and contribute to analysis paralyzis trying to figure out how many skills and levels you truly can have, and where to put those points.

One way around this is to avoid giving players points during character creation and simply say "Pick X amount of Skills. These Skills start at level Y*" (/The End). That way there's zero math involved during creation and you only have to deal with skill costs during character progression, where handling variable skill costs is far more manageable.

Exponential skill cost being too high (eventually), as Steven Mitchell points out, is a valid concern. But this depends a lot on how high skills can get in the system. If skills can only get to like level 6 or so I don't think it matters too much (if 10 or so the cap, you could also say XP Cost = 1/2 Levels, which is only marginally more complicated). And prohibitive costs for higher levels helps limit excessive level ups and somewhat simulates skill improvement getting more difficult the better you get at them, while encouraging branching out. So there's that to consider.

*where "Y" is basically the average level in the game/max starting level allowed.

Quote from: Krugus on March 11, 2022, 07:53:42 PM

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.

Honestly, it amounts to the same thing, with slightly more granularity. Hell, you could houserule it by just knocking the last zero off and calling it a percentage.

My game Simple Superheroes uses a . . . simple "skill" progression. Everything is based on Talents which range from 1 (no talent) to 5 (roll 5 dice).

Here's the costs:

Increase Talent to Rank	Experience Point Cost
2	5
3	8
4	11
5	14

The escalating cost here works pretty well for a few reasons:

• High ranked skills tend to be ones the characters roll/rely on a lot.
• 5 is the cap.
• Each die is capable of generating additional affect (a success). 4 success on a "punching" roll would be 4 damage.
• Getting 3 successes against someone is often permanent, whereas a single success is transient. (3 successes disarming someone might break a gun, or knock it into a sewer grate, whereas 1 success means it could be recovered relatively easily.)
• Each rank is x2 as strong* (at least) as the prior rank in terms of what it can do.

I do sometimes think that the 4 to 5 cost is to steep. That's a lot, and most advances will be adding 2's or bumping a 2 to a 3. But it can make characters who use a starting array that includes a 5 feel the choice was worth it.

There are also "Relations" and these have there own progression. A relation is usually only rolled once a session (sometimes not at all, rarely twice) and can be used to recover Strainpoints. "They also receive 1 Relation point every 3 - 4 sessions. Relation points are exchanged for Relation ranks on a 1 for 1 basis, except rank 5 costs 2 points." Meaning advancing a rank 3 relation to rank 4 is just one point.

*the multiplier depends on the power level you set your game at.

For a little extra context go grab the Heart of Simple Superheroes 4 page download.

 I think point-for-point is perfectly fine. The dirty little secret is, you don't to impose diminishing returns. Diminishing returns is something that is unavoidable. One of the points I frequently make about AD&D 1st Ed, for example, is that the majority of monsters in the original MM have AC 5 or worse. Once a fighter hits 7th-9th level (depending on exact attributes and magical items) they can often hit AC 5 on a 2 or better. Beyond that point, they don't get any better at hitting most monsters. And the list of monsters for which they do get better at hitting keeps getting smaller and smaller.

Likewise, damage in excess of the target's hit points is wasted. When you get to the point where a lot of things are one-hit-kills, most of your increases in damage beyond that point is going towards wasted damage. Diminishing returns. Party thief has a certain chance of picking a lock. But you've also got a magic-user with a knock spell or two as a backup. Once you hit the point where the thief's pick locks percentage is high enough that you're able to pick all but two of the locks you encounter on an average adventure, beyond that you're diminishing the utility of pick locks.

In skill based games in general, assuming your skill set itself is well designed, there's only so much one particular skill can do with regards to progress in a given adventure. Once you've got enough skill to nullify or solve that area of challenge or difficulty, piling extra points into it no longer helps, nor does it address the areas of challenge or difficulty to which that skill cannot be applied. If you're finding this problem doesn't take care of itself, you might want to look back at the skill set itself.

Quote from: Lunamancer on March 15, 2022, 11:23:36 AM
I think point-for-point is perfectly fine. The dirty little secret is, you don't to impose diminishing returns. Diminishing returns is something that is unavoidable. One of the points I frequently make about AD&D 1st Ed, for example, is that the majority of monsters in the original MM have AC 5 or worse. Once a fighter hits 7th-9th level (depending on exact attributes and magical items) they can often hit AC 5 on a 2 or better. Beyond that point, they don't get any better at hitting most monsters. And the list of monsters for which they do get better at hitting keeps getting smaller and smaller.

Likewise, damage in excess of the target's hit points is wasted. When you get to the point where a lot of things are one-hit-kills, most of your increases in damage beyond that point is going towards wasted damage. Diminishing returns. Party thief has a certain chance of picking a lock. But you've also got a magic-user with a knock spell or two as a backup. Once you hit the point where the thief's pick locks percentage is high enough that you're able to pick all but two of the locks you encounter on an average adventure, beyond that you're diminishing the utility of pick locks.

In skill based games in general, assuming your skill set itself is well designed, there's only so much one particular skill can do with regards to progress in a given adventure. Once you've got enough skill to nullify or solve that area of challenge or difficulty, piling extra points into it no longer helps, nor does it address the areas of challenge or difficulty to which that skill cannot be applied. If you're finding this problem doesn't take care of itself, you might want to look back at the skill set itself.

Those are some really good points.  Unlike D&D, margin of success is very important in my game (frex MoS = damage on an attack roll), but once you get to the point of a one-hit kill, more doesn't help at all.

Right now I'm leaning towards 1 pt for skills 1-10, 2 pts for skills 11-20 and 3 for 21-30.  The progression will go on, but the game is built around the idea that 30 is about the limit of human capability.