SACK

Sack is violent version of the game, invented by a group of young boys at Gosford High School, N.S.W., Australia. When a player makes a mistake they are given a letter, for example, for their first mistake they receive an "s". After they spell out "sack" (or another designated word) the player has to stand still while all players participating in the game get to throw the hacky at the offending player.