A gamemaster (GM; also known as game master, game manager, game moderator or referee) is a person who acts as an organizer, officiant for regarding rules, arbitrator, and moderator for a multiplayer role-playing game. They are more common in co-operative games in which players work together than in competitive games in which players oppose each other. The act performed by a gamemaster is sometimes referred to as ''Gamemastering'' or simply ''GM-ing''.

What's the best answer to this question: is there such thing as a game master?
yes