Boxing, also called pugilism, is a combat sport in which two people engage in a contest using only their fists. There are two forms of boxing: amateur and professional. Amateur boxing is an Olympic and Commonwealth sport and is a common fixture in most of the major international games – it also has its own World Championships. Boxing is supervised by a referee over a series of between one to three minute intervals called rounds. The result is decided when an opponent is deemed incapable to continue match by a referee or if an opponent is disqualified for breaking a rule, resigning by throwing in a towel, or by judges’ scorecards at the end of the bout.