American football is a team sport played with an oval ball on a rectangular field, where two teams of eleven players try to advance the ball into the opponent's end zone to score points. The offense gets four chances, called downs, to move the ball at least ten yards. If they succeed, they get four more downs. If they fail, the other team gets the ball.

Unlike soccer (which most of the world calls football), players can carry the ball in their hands, throw it forward, and tackle opponents to stop them. The game stops after each play, then both teams line up again. This start-and-stop pattern makes American football more like chess than constant-motion sports: coaches call specific plays, and players execute carefully planned strategies.

Games are divided into four fifteen-minute quarters. Teams score six points for a touchdown (getting the ball into the end zone), three points for a field goal (kicking it through the tall yellow goalposts), and two points for a safety (tackling an opponent in their own end zone). The Super Bowl, the championship game played each February, is one of the most-watched sporting events in America.

The sport developed in American colleges during the 1800s from rugby and soccer. Today, millions of kids play it in youth leagues and schools, while professional and college games draw huge crowds every fall and winter.