Rock Paper Scissor battles. You take your stat, you attack someone else's stat (not neccessarily the same one). You choose Rock/Paper/Scissors against their defense, which doesn't change. If you win, you get +1. If it's a tie, +0. If you lose, -1.

I was scum in the Dresden Files game, and I dealt with the both the highs and the lows of the system. On the one hand, I had an extremely unlucky run of nights- almost just like now, in fact.

On the other hand, even after everyone figured out I was scum, I think I managed to survive about 3 attempts on my life before I was eventually done in.

So, yeah. Maybe they have an every other night ability, maybe FT's mystery ability did something, but I wouldn't be surprised if a failed RPS roll was responsible for at least one of the murderless nights.