Game master (GM, ref)

A game master (GM, or ref) is one of the people who run a larp, managing the story, answering rules questions and keeping play safe.

Game masters plan and run the story, brief players, play or direct non-player characters, and make calls when a rules question comes up. A small game may have one GM; a large event will have a team, with some people on story, some on rules and some on safety or logistics. The title changes from game to game. Ref (short for referee) is common in the UK, while other games say GM, staff, storyteller or simply plot. Whatever they are called, they are who you go to when you are unsure of a rule or something feels unsafe.