The argument for exponential skill costs

[Anthony]

GURPS 4e skill costs are on a doubling scale for the first two levels before turning flat; physical skills in 3e actually had four doublings. There is, however, a reasonable argument for keeping doubling forever.

This basically amounts to how you define define what it even means to be point balanced. There are two basic methods: you balance against the world, or you balance against player preferences. The first is very hard to do and tends to wind up with quite variable costs, but the second has some known solutions.

Consider a simple analogy: points are raffle tickets. When a game starts, you put as many tickets as you want into a bunch of pots that represent skills. When a skill challenge comes up, the GM reaches into a pot and pulls out a ticket, and whatever ticket the GM pulls out was the most successful. The GM might also toss tickets into the pot, in which case a GM ticket being pulled out means none of the player succeeded.

If player A puts 2 tickets into a pot and player B puts one, player A wins 2/3 of the time. If player A puts twenty tickets into a pot and player B puts ten, again, A wins 2/3 of the time.

Since the odds of winning in a GURPS style quick contest is purely a function of relative skill, this suggests that doubling your points spent should produce a flat skill bonus.

As for what bonus that should be: a quick contest with a skill difference of 0 is even odds (with about 10% ties). For other common differences:

1. 1.5:1
2. 2.3:1
3. 3.5:1
4. 5.5:1
5. 8.9:1
6. 15:1

This is somewhat slower than doubling every +1, but remember that skills in GURPS come from adding stat and skill, so someone who puts twice as many points in a skill and also puts twice as many points in a stat would get a +2.

There are a number of aspects of this that would need more development (for example, fighting ability is not just a function of combat skill, it also depends on ST and HT and other abilities) but it seems like a reasonable start point for discussion.

[Anthony]

Originally Posted by Agemegos

On the other hand, GURPS already has a serious problem with the mismatch between an extremely lumpy set of attributes and an extremely splitty profusion of skills, specialities, techniques, and manœuvres, which imposes a strong incentive on players to build characters with super-cinematically high attributes. Making high skill levels even more unattractive would exacerbate this problem.

Not if you're doing the same thing to stats. Sure, it might cost 16 points to go from stat+3 to stat+4, but if it costs 160 points to go from stat 13 to stat 14, you might still raise the skill...

[Aldric]

Originally Posted by Anthony

Not if you're doing the same thing to stats. Sure, it might cost 16 points to go from stat+3 to stat+4, but if it costs 160 points to go from stat 13 to stat 14, you might still raise the skill...

Or they might not raise anything, since they will not have the points for it, might as well cap attributes at that point, and if you want to keep doubling the cost of skills, cap those as well, it's faster.

[Anthony]

Originally Posted by Aldric

Or they might not raise anything, since they will not have the points for it, might as well cap attributes at that point, and if you want to keep doubling the cost of skills, cap those as well, it's faster.

You'd probably change the xp system. Exponential costs certainly are a major change that you wouldn't want to introduce by itself with no other adjustments, but that doesn't mean it's wrong.

Originally Posted by Agemegos

It's very hard to buck the trend in a system in which it requires six skills to be a chef.

As long as both stats and skills are on an exponential scale, it will always eventually be more efficient to raise both.

[zoncxs]

Originally Posted by Agemegos

It's very hard to buck the trend in a system in which it requires six skills to be a chef.

It requires over six skills to be a Lawer.

over six to be a Soldier.

etc.

There are very few jobs that require few skills to do, let alone so few skills to learn to do said job.

The way around this would be to use wildcard skills.

[David Johnston2]

Originally Posted by Agemegos

It's very hard to buck the trend in a system in which it requires six skills to be a chef.

While gardening might be slightly useful to a chief it is hardly required.

[AlexanderHowl]

What problem is exponential skill cost supposed to be solving exactly? There is already a doubling of cost every level up to 8 CP, but it plateaus at 4 CP per level due to diminishing returns. The only thing that I can see it doing is making advantages and techniqiues more attractive.

For example, let use say that every level in a skill and attribute costs twice as much as the previous one. At HT 12 [20] and Sex Appeal (A) HT+2 [8]-14, I am paying 28 CP for attribute plus skill. To increase Sex Appeal to 20, I either spend an extra 1260 CP on HT or an extra 504 CP on Sex Appeal. Or I can spend 30 CP on Allure 4 and Voice.

[Anthony]

Originally Posted by AlexanderHowl

What problem is exponential skill cost supposed to be solving exactly?

What makes you think I was posting about solving a problem?

[Not another shrubbery]

Originally Posted by Anthony

You'd probably change the xp system. Exponential costs certainly are a major change that you wouldn't want to introduce by itself with no other adjustments, but that doesn't mean it's wrong.

As long as both stats and skills are on an exponential scale, it will always eventually be more efficient to raise both.

You'd have to jigger the costs of advantages too, wouldn't you? To keep them comparable to the inflated premium on higher skill and stat levels?

[Anthony]

Originally Posted by Not another shrubbery

You'd have to jigger the costs of advantages too, wouldn't you? To keep them comparable to the inflated premium on higher skill and stat levels?

Or you could just have a game with lower skill and stat levels. The main problem is with abilities that provide a flat bonus, you obviously need to rework thinks like Talent.

It would probably work better to change the die rolling mechanism so linear skill cost is actually appropriate, though this is challenging for other reasons.