World of Warcraft: Wrath of the Lich King, often referred to as WotLK, or Wrath, is the second expansion set for the massively multiplayer online role-playing game (MMORPG) World of Warcraft, following The Burning Crusade. It adds a substantial amount of content to the game world, including the continent of Northrend, home of the eponymous Lich King, and a new character "hero" class.