Football is a sport that involves running, passing and kicking. It is played at both a professional and amateur level, with teams in the United States, Canada, Japan, Europe, Mexico and the Pacific Islands.
The game is divided into two halves, each 45 minutes long, and players take a 15-minute rest period at the end of each half. There are also rules that determine how many plays may be played in a given time frame.
During each play, the ball is snapped between the offensive and defensive lines of the field. The ball-carrier (usually the quarterback) runs with the ball while other team members, called ball-carrying teammates, run behind him to help carry the ball.
Once the ball has been carried, the quarterback will usually try to pass the ball to a receiver who is in position to catch it. The receiver may or may not catch the ball; either way, the offense will continue to advance towards the opposing team’s end zone, where they can score a touchdown and earn six points.
In order to move forward and score a touchdown, the offensive team must be able to gain at least 10 yards during the four downs they are awarded. Once the offense is able to reach 10 yards in the fourth downs, they will be given another four downs to gain more yards.
Penalties are a common feature of football, and are signaled by referees. The referees throw yellow flags onto the field near where the foul occurred, and additional penalties are indicated by the same official throwing a beanbag or a hat.
During a play, a player can receive a penalty for a number of reasons, including illegal holding, offsides and pass interference. The penalty can cost the team between 5 and 15 yards of field position, so avoiding penalties is vital to the success of the play.
A sack occurs when a defense tackles the quarterback before he is able to pass the ball. Often, the defensive line will blitz the quarterback in an effort to stop him from passing or running with the ball.
When a sack occurs, the opposing team is called down, and they may be given an automatic first down. If the team continues to run with the ball, a safety is scored by the defense for 2 points.
The offense can kick a field goal, worth three points. It can also attempt a touchdown, which is worth six points.
At the end of a touchdown, teams are given an option to kick a field goal for one extra point or attempt another touchdown from the same end zone. If a field goal is made, the offense will be awarded two points; if not, the team will be awarded none.
In the United States, a touchdown is worth 6 points, but in some countries, it can be worth only two points. Similarly, in some countries, a fumble is only worth two points.