A referee is an official, in a variety of sports and competition, responsible for enforcing the rules of the sport, including sportsmanship decisions such as ejection. The official tasked with this job may be known by a variety of other titles depending on the sport, including umpire, , arbiter (chess), commissaire, or technical official (by the International Olympic Committee). Referees may be assisted by umpires, linesmen, timekeepers, or touch judges.