GreatLemur
Explorer
True20 has something like this going on. Some supernatural powers as designated as "fatiguing", and require the user to make a Will save each time they're used. Failure, of course, means increasing levels of physical fatigue. And, every time you use such a power, you collect another cumulative +1 to that save DC.Ravellion said:What about reverse spell points? Instead of depleting spell points, with the caster no longer being able to cast when they've all been used up, add up "spell fatigue points".
Some spells could add more points, and you could install penalties for having high "spell fatigue points", like a spell failure chance, that would increase all the way to 100% if someone is at 10x his "spell fatigue comfort zone".
But the way you worded your idea makes me think about about something completely different. What if the limiting factor of magic wasn't that using it drained you of something, but that you instead accumulated something bad. I don't mean like a taint/corruption mechanic, so much as a magical residue or radiation. You don't spend magic points; you take them on. As they stack up, they impose unwanted modifiers on various things. They could be applied as a penalty to things like social skill checks and saving throws, or constitute the DC of some kind of magical mishap check. Might be fun if it had some small, specific positive effect, too, like an Intimidation bonus.