The precise definition of what separates a sport from other leisure activities varies between sources. The closest to an international agreement on a definition is provided by SportAccord, which is the association for all the largest international sports federations (including association football, athletics, cycling, tennis, equestrian sports, and more), and is therefore the de facto representative of international sport.
SportAccord uses the following criteria, determining that a sport should:
have an element of competition
be in no way harmful to any living creature
not rely on equipment provided by a single supplier (excluding proprietary games such as arena football)
not rely on any "luck" element specifically designed into the sport.
They also recognise that sport can be primarily physical (such as rugby or athletics), primarily mind (such as chess or go), predominantly motorised (such as Formula 1 or powerboating), primarily co-ordination (such as billiard sports), or primarily animal-supported (such as equestrian sport)