At the beginning of the game, every player has a dangerousness rating of zero. Every time a player scores a legal kill, his dangerousness goes up by one. Getting killed will lower your dangerousness by half, although the lowest rating a player can have is zero. Also, if a player is inactive for a long time, his dangerousness rating will start to deteriorate at a slow rate.
Every time a player gets killed, he will lose one sixth of his points. These points are then awarded to his assassin, multiplied by a factor determined by the victims dangerousness. Thus, you get more points for dangerous players. The victim, however, will only lose the said one sixth of their score.
A player will lose ten points for each illegal non-player kill.