Player killer

A player killer, or PK for short, is a player who exists in an online role-playing game (such as a MUD or MMORPG) to kill other player characters. (PKs kill the characters of other players, not the players themselves.) This type of player is usually motivated by the inherent difficulty in hunting 'live' prey, the in-game rewards gained, and/or the satisfaction felt from causing another player grief.

Players have mixed feelings over player killers. In some instances, player killing is an enjoyable part of the game. Various MUDs encourage player versus player combat. PKs are not always desirable though (especially when the intent is to cause another player grief). Complaints over PKs in Ultima Online probably influenced the developers of EverQuest to disallow nonconsensual player versus player combat by default.

Other games with player killers: Diablo II