Game master

"Game master," "gamemaster," or simply "GM" is a title for the officials in an online RPG (role-playing game) which refers to those in power in a game whom do any of the following: devise rules and regulations for the game and design how the gameplay will be (developer), enforce those rules and regulations (moderator), or had a hand in developing the game's scripts itself (coder). Not to be confused with "Master Gamer," who is simply a player who has mastered the game (a person that is extremely good at the game that has had no hand in the workings of the game).