A griefer is a player in a multiplayer video game who deliberately irritates and harasses other players within the game, using aspects of the game in unintended ways. A griefer derives pleasure primarily or exclusively from the act of annoying other users, and as such is a particular nuisance in online gaming communities, since griefers often cannot be deterred by penalties related to in-game goals.
In the culture of massively multiplayer online role-playing games (MMORPG) in Taiwan, such as Lineage, griefers are known as "white-eyed"—a metaphor meaning that their eyes have no pupils and so they look without seeing. Behaviors other than griefing which can cause players to be stigmatized as "white-eyed" include cursing, cheating, stealing, and unreasonable killing.
The term was applied to online, multiplayer computer games by the year 2000 or earlier, as illustrated by postings to the rec.games.computer.ultima.online USENET group. The player is said to cause "grief" in the sense of "giving someone grief".