In which sport is the field oval-shaped?

Australian rules football, officially known as Australian football, or simply called "Aussie rules", "football" or "footy", is a contact sport played between two teams of 18 players on an oval field, often a modified cricket ground. Points are scored by kicking the oval ball between the middle goal posts (worth six points) or between a goal and behind post (worth one point).

Australian rules football playing fields have no fixed dimensions but at senior level are typically between 135 and 185 metres (148 and 202 yd) long and 110 and 155 metres (120 and 170 yd) wide 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 having too many players from one team on the field. In addition, some leagues have each team designate one player as a substitute who can be used to make a single permanent exchange of players during a game.