Methods of Improvement

I already had a system in place that would allow a character's Faith score to be malleable through the course of normal play, changing the score based on exceptional success or exceptional failure with Turning checks. Just today I wrote down and implemented a similar idea for the Luck stat, where the Luck would alter with exceptional critical hits (consecutive natural 20s), or exceptional critical fumbles (consecutive natural 1s).

I also allow stats to be built up using Combat Proficiencies (my term for Weapon Proficiencies, Non-Weapon Proficiencies, or Feats, depending on your chosen version. I don't know what the 4th Ed. equivalent is, but I don't care), but since I have these two stats as potentially variable I was wondering if there were other stats that people thought should be so quickly alterable. I know that physical stats such as Strength should not be so quickly or easily changed, but maybe Charisma might be affected by apparent wealth, or the Charisma scores of the people you're with?

Probably not, since it's a bit trickier than the systems I have in place for Faith and Luck. As it stands, Faith is really only important to one class, or anyone who wants to Turn or Rebuke undead. Luck is a bit more universally useful, since it affects saving throws, but there are two classes in particular that are majorly helped by having Luck as a primary stat. I like having these two stats alterable on-the-fly because I think it reflects the concept behind them well, but I don't know that any of the others really lend themselves to such.