Griefer

A griefer is someone who seeks to anger and irritate other players. In Guild Wars, a common example of this is someone who quits a PvP or PvE team shortly after joining the game, with no explaination. In PvP, sometimes a griefer will utilize skills to kill him or herself, which can score points for an opposing team in some arenas and may waste a teammate's Resurrection Signet. Other methods of inducing irritation and anger include: scams, harassing other characters (sometimes visually via emotes), and rushing intentionally into unbeatable odds in PvE.

During the Factions Preview event. Griefing was rampant as people from either faction would join an opposing faction team for Faction Battles, then instantly leave at the start of the match.