What Do You Call Someone Who Enforces Game Rules?

Formal Titles

• Referee (most sports)
• Umpire (baseball, cricket, tennis)
• Judge (chess, dance, gymnastics)
• Moderator (online games/forums)
• Official (umbrella term)

Informal / Contextual

• Rule enforcer
• Game master / GM (tabletop RPGs)
• Watcher (neutral observer)

Pick the term matching your game's tradition.