Something a group of us used to play at school (I was the Commisioner.) It is kind of like LARP, in that we added score bonuses for spectacularly conniving, sneaky or risky kills. If you take this to your own school, office place or group of friends, please remind them that it is only a game, not to be taken seriously and no harm should be done to any players.
Oh and I take no responsibility if this goes badly.

Wasn't this a Steve Jackson game?
Didn't Steve Jackson Games put out a game called 'Assassin' or some similar title?
Peace, Errin : )
http://www.1km1kt.net/Errin-Famiglia.htm
Adventuria Online RPG