Comparison of American football and rugby union possession of the ball at their own 20-yard (25 yard line in College Football) line. An important difference between the two sports involves the aftermath of a score. In American football, the scoring team kicks off, except after a safety. In rugby union, the team conceding the score kicks off (in rugby sevens, a variant of rugby union featuring seven players per side, the scoring team kicks off). An American football team consists of an offensive unit, a defensive unit and a "special teams" unit (involved in kicking and kick returns). Only eleven players can be on the field at
Australian rules football wing-to-wing. The field, like the ball, is oval-shaped, and in Australia, cricket grounds are often used. No more than 18 players of each team (or, in AFL Women's, 16 players) are permitted to be on the field at any time. Up to four interchange (reserve) players may be swapped for those on the field at any time during the game. In Australian rules terminology, these players wait for substitution "on the bench"—an area with a row of seats on the sideline. Players must interchange through a designated interchange "gate" with strict penalties for too many players from one team on