Boxing is a martial art and combat sport in which two people wearing protective gloves throw punches at each other for a predetermined set of time in a boxing ring. Amateur boxing is both an Olympic and Commonwealth sport and is a common fixture in most international games—it also has its own World Championships. Boxing is supervised by a referee over a series of one- to three-minute intervals called rounds. The result is decided when an opponent is deemed incapable to continue by a referee, is disqualified for breaking a rule, resigns by throwing in a towel, or is pronounced the winner or loser based on the judges' scorecards at the end of the contest