- Football (general): Any of a number of team sports which involve kicking and/or handling a ball with the purpose of territorial gain leading to the scoring of goals or points.
- Football (soccer): A sport in which two teams, each consisting of 11 players, compete to move a spherical ball around the playing field and into their opponents' goal; with the exception of the goalkeeper, players may not use their hands or arms to control the ball.
- American football: A high-contact sport played by two teams of 11 players on a 100-yard field that originated in the United States of America.
- Australian rules football: A form of football involving two teams of eighteen players on an oval-shaped field. Players can kick or handle the ball.
- Canadian football: A variant of American football that is played on a field that is wider and longer and with 12 players on a side.
- Gaelic football: An outdoor sport played by two teams of 15 players a side. It is a form of football using a round ball which the players may both handle and kick, with the object of kicking or punching the ball into the goal.
- Rugby league: A form of rugby football played in teams of thirteen. It began in 1895 as a breakaway sport from rugby union on the issue of professionalism.
- Rugby union: The original form of rugby football played in teams of fifteen. It was strictly amateur until 1995 when it opened up to professionalism.
- Football to 1900: A history of football's development through the 19th century from a folk activity into its modern variants.
In rugby, 15 players are on the field for the 80-minute game, and the ball cannot be passed forward in a game. A rugby ball is oval, 27cm long, weighs about 1 lb., and its ends are flatter than an American football.
In American football, 11 players are on the field for the 60-minute game, and points range from 6 points (touchdown) to 1 point (kick). The football is oval, 29cm long, weighs a few ounces less than a rugby ball, and its end comes to a point.
Soccer (British football)
In soccer (British football), 11 players are on the field for the 90-minute game, and players cannot use their hands. A round ball is used.