(abbreviated GM) the facilitator for a role playing game. the one who determines or decides what happens in a role playing game. the one who runs a role playing game. contrasts with player.
the person(s) running and controlling the overall game
GameMasters are staff that run events and sometimes fix character-side problems in the MMORPG.
hired professional who work to help players when they face some difficulty in game (caused by bugs or technical problems)
(also GM) In the world of the RPG, the GameMaster is god, king, or whatever other ruling figure you wish to compare him (or her!) to. They create and describe the setting the player's characters live in, enforce the game rules, keep track of the various game events, control the monsters and non-player characters that the players run up against, and eventually go completely insane because of the massive amount of work that the job entails. But don't listen to all their whining . . . they love it. Now, with the description out of the way, I want to go over what a GameMaster is NOT. Outside the game, the GM has no control over the players. They aren't some grand high poobah leader over the players in any way, form, or fashion. Why anyone would try to equate a GM with, say, a cult leader . . . it's completely beyond me. Some of us may wish we had that kind of control over the players (haha, kidding!), but we really don't. Yeesh.