Original sentence: An act of griefing usually meets all these criteria as well as any game specific criteria set by the developers of the game.Griefing is a form of emergent gameplay.The perpetrator must have an advantage that was not intended by the developers of the game to exist.The use or abuse of a game mechanic that was not intended by the game's developers
Edited sentence: An act of griefing usually meets all these types of criteria as well as any game specific criteria set by the developers of the game.Griefing is a malignant form of emergent gameplay.The perpetrator must have an unfair advantage that was not intended by the developers of the game to exist.The unfair use or abuse of a game mechanic that was not intended by the game's developers