Dungeon Master

In the Dungeons & Dragons (D&D) role-playing game, the Dungeon Master (DM) is the game organizer and participant in charge of creating the details and challenges of a given adventure, while maintaining a realistic continuity of events. In effect, the Dungeon Master controls all aspects of the game, except for the actions of the player characters (PCs), and describes to the players what their characters experience. Regular Dungeons & Dragons groups consist of a Dungeon Master and several players. The title was invented by Tactical Studies Rules (TSR) for the Dungeons & Dragons RPG, and was introduced in the second supplement to the game rules (Blackmoor) in 1975. To avoid infringement of trademarks by the publishers of Dungeons & Dragons, and to describe referees in role-playing genres other than sword and sorcery, other gaming companies use more generic terms, like Game Master (GM), Game Operations Director (a backronym of GOD), Judge, Referee or Storyteller. Some use more esoteric titles related to the genre or style of the game, such as the "Keeper of Arcane Lore" from Call of Cthulhu and the "Hollyhock God" from Nobilis.