Introduction to American Football Basics
The Field is 100 yards long (and 160 feet wide). The middle of the field is the 50 yard line. The lines are labeled every 10 yards descending in both directions from the 50 yard line.
The "zero yard line" is called the goal line. The areas to either side of those 100 yards, extending 10 yards past the goal lines, are called the end zones. Teams try to get the ball past the opponent's goal line into the end zone to score a touchdown.
Kickoffs: At the start of the game there is a coin toss to see which team gets the ball first. The team that has the ball is the offense; the other team is the defense. The game is divided into 15 minute quarters with a major division at 30 minutes which is called half time. At the end of the first and third quarters, the players merely switch sides.
Downs: The offense has 4 plays or downs to cover 10 yards or more. A play ends when the player with the ball is either stopped or goes out-of-bounds or if the ball is thrown and missed (which is called an incomplete pass). A player is stopped when his knees touch the ground either because he was tackled by a defensive player or because he fell. If a team succeeds in advancing 10 yards or more, they get a first down. That is, they get a new set of 4 downs to make another 10 yards.
Scoring: The object of the game is to score more points than your opponent. A touchdown is worth 6 points. After a touchdown, the team then attempts to kick the ball through the goal posts to get an extra point.
A field goal is worth is worth 3 points.
If an offensive player is stopped in his own end zone, the defense scores a safety which is worth 2 points.
The Players: Each team has 11 players on the field.
The players come up to the line of scrimmage which is an imaginary line drawn from one side of the field to the other through the tip of the football closest to the defense. Each team must stay on their own side of the line of scrimmage until the play starts.