Ultimate (sport)
The World Flying Disc Federation (WFDF) controls the rules of play and game structure for international competitions. However, players of ultimate are individually responsible for upholding the rules of ultimate. Unlike other sports, there are no referees in ultimate. Players must call their own fouls or infractions and must resolve conflict by communicating directly with the opposing team. All  players are expected to follow the Spirit of the Game, which describes how fair play is critical to ultimate.