Football is a team sport played between two teams of 11 players on a 120-yard field, with goal lines on each end. The game is controlled by a referee, who signals when the ball goes out of play and when players are offside, and by assistants who patrol the touchlines and sidelines.
The game is played with a ball, which is oval-shaped and is made of rubber or cowhide. It is a fast-paced sport with many variations in rules, but consists of four basic actions: running, passing, and catching the ball.
Passing the ball is a major goal of the game, as it allows the offense to advance toward the opponent’s goal line and score points. The ten outfield players (four defenders, four midfielders, and two forwards) must be organized into a certain set of positions to achieve this goal.
Each team has a quarterback, who leads the team in passing. The quarterback must be able to throw the ball accurately, allowing it to go over the opponents’ head and into the opposing team’s end zone for a touchdown.
Running the ball is another important part of the game, as it allows the team to move down the field while avoiding opposition defenses. The player who carries the ball can run up to a certain distance, called the “penalty line”; the player must then sprint or jump over the penalty line in order to gain yards for their team and continue the play.
The runner’s route is usually designed by the quarterback, but the offensive player can make adjustments to his own path as he runs down the field. Depending on the play, the route may be short and easy, or long and difficult to execute.
Several other types of runs can also be used, including sweeps, where a player tries to run behind an opposing defender; laterals, in which the runner runs against a specific direction with the goal of moving across the opponents’ defense; and a reverse run, where a runner uses the backswing of his legs to pull himself over an opposing defensive defender.
A defensive player may also take a “sack,” or “flounder,” which is a fumble, when he catches the ball while under control. A sack is the most common type of fumble and occurs when the defensive player pulls the ball from the quarterback’s hand, preventing him from advancing towards the opposing end zone.
There are several other types of fumbles, including a kickoff, which is when the ball is thrown into the air, and an interception, in which the defensive player intercepts a pass and runs it backwards to the opponent’s end zone. These are more dangerous and often result in a touchdown, but are less frequent than fumbles.
In the United States and some countries of Europe, a professional league is operated; in some other regions, such as Mexico and American Samoa, amateur clubs and youth teams are used to practice and to compete. In addition, some countries operate cup competitions during the season, which are played on a knock-out basis.