The problem is merely gains on success, which breed more success, which breed more gains.
The proper way to skill up is on skill failures, so that as you succeed more, gains become less frequent and harder challenges must be sought. Swear to god there's one or two lines of code where this can be changed. Instead of hits, gain on the misses.
This is the smartest programming idea I have heard in a while. Do you mind if I steal it?
Oh, the idea is not really mine, so I guess it's public domain. I've seen in it several games.
@Trollheiming
I am sorry to burst your bubble but that would not remove the grind but instead make it longer.
Depends on the particular skill implementation, doesn't it? It can potentially eliminate the grind. Evasion, for example. Suffice to say, if a guy always dodges against a weak opponent, then he can skill up without risk on unlimited risk-free successes. But if he has to take damage in order to skill up, it becomes a risk.
Additionally you can add an offset: on a die of 100 against your evasion skill, only gain when the hit roll calculation was +10 over the threshold. By the time your dodge is good enough that you can avoid 90% of the shots, you get zero returns on your grinding. You only skill up when there's a chance of seriously failing a roll.
I enjoy boarding actions, myself; always fun to send people over to destroy the other ship from the inside out. It isn't so fun to end up LOSING my squad when the enemy vessel explodes on accident, though.
I prefer causing a lot of fires and gloating as my enemies rush around burning themselves to death in the hopeless battle against the inferno.