[khorboth]

For low-powered things, a once-per-session luck roll could be good. Silver charms can give one use per session on a damage or ST roll. Being too greedy with charms nets to a bad luck roll.

Perhaps work up a Karma stat. Start at zero and then get +1 for doing the good thing, -2 or -3 for doing the wrong thing, nothing for doing the expected thing. Keep a total and spend the points on luck rolls? perhaps 10 points for a single use of luck?

I like the luck mechanic because it doesn't let anybody do the impossible or really push their maximum capabilities. It can easily fly under the radar socially while still being a real game affect.

hidden lore (Karma) might be good for spotting the opportunities to get the bonuses.