Roll-modifying down is probably my fault.
I think I remember that you can use YYs to lower the damage you take and increase the whupass you hand out (I don't keep my game books at work for some odd reason, but I'll check when I get home.) Thence I extrapolated.
I also let the players spend their YYs to influence other players and GMCs. That probably comes from my brother's Matrix Game mechanics.
(I am not responsible for "1YY for a reroll." That was a con game practice that predates me.)
All in all, and I want to reread the pertinent section in the Holy Game Book, I have not found any of this to unQAGSify the game. To the contrary, I find it has helped to promote a sense of collaborative storeytelling. Especially at Fairy Tale/Noir this past weekend (That book is so going to rock.)
I'm a BAD IAN
