Step 1: The Object of the Game
In the game of American football, two teams compete to score points by moving a ball into the end zones of their opponents—either passing the ball from one player outside the end zone to another who's inside, running the ball from the playing field into the end zone, or sometimes kicking the ball through an end zone's goal posts. But more on scoring later.
Each team has 11 players on the field.
Smaller teams or leisure players may compete with eight or fewer participants.
The team with the ball at any given time is called the offense.
The other team, which tries to stop the offensive advance and "defend" its end zone, is called the defense.
Step 2: The Set Up
Regulation football fields (minus the end zones) are 100 yards long. Each end zone contains a goal post and is 10 yards long. Yards are measured from each respective end zone's goal line, beginning with 1, until yard markers meet in the middle at the 50 yard line.
Though all yards are measured with "hash marks" or white lines on the sidelines, plus a line extending across the width of the field every five yards. Only every 10th yard line (10, 20, 30, etc.) is labeled with a numeral.
A football field. (Creative Commons photo by Christopher)Play time:
The length of a football game is divided between two halves, each with two quarters. In professional football (NFL), along with college (NCAA) and arena football, each quarter in a game is 15 minutes long with a 12-minute half time between the second and third quarters. High school teams, however, play 12-minute quarters in a 48-minute game. Participants in amateur leagues or friendly games may shorten these periods.
When there are two minutes of play remaining before the end of each half, respectively, officials signal for a "two-minute warning." This stops the clock and serves as a free timeout for the teams.
An additional overtime play period is added if the teams are tied at the close of the fourth quarter.
To stop the clock, teams are allotted a number of timeouts (three per half in the NFL). In addition, some plays, such as running the ball out of bounds or scoring, can stop the clock (Arena Football has exceptions to this rule).
At the beginning of each half, and after every time a team scores, that team kicks the ball at their own 30-yard line to the receiving team. The receiving team, or offense, can then run the ball as far as they can toward the defensive team. The play ends either when the player who caught the ball is stopped by the defense or if he scores.
It is illegal to kick the ball outside the lines of the playing field, so consequently, when that happens, the receiving team automatically gets to start their possession on the field where the ball went out of bounds or 30 yards from where it was kicked off.
If the ball is kicked into the receiving team's end zone, the receiver can either run the ball or go down on one knee. When he does this, it's called a touchback. It means the play is over and the ball will be placed at the 20-yard line for the next series of plays. A touchback is also the result of kicking the ball out of bounds in the end zone.
A team moves the ball toward its goal by having the quarterback (see "The Players" below) either pass the ball or hand off the ball to another player, who then runs as far as possible without getting tackled. When the quarterback throws a pass that either lands on the ground before its caught or is caught out of bounds, it's ruled an incomplete pass. A team cannot advance as a result of an incomplete pass, but instead must re-play that down.
In one possession, the offense has four tries to move the ball forward 10 yards. These tries are called "downs" and are measured at the end of each play by linesmen (non-playing judges on the sidelines). Each time the offense successfully moves the ball forward at least 10 yards from where they started that series, it is a first down and players are rewarded with a fresh set of downs to continue their advance. The "line of scrimmage" refers to the location on the field where the ball is placed (then each team lines up and a play is set in motion).
The team with the ball can always exceed 10 yards, but if it has not advanced the ball that distance after three downs, the players can either "punt" (kick the ball down-field to the other team), attempt a field goal if they're in range (see "Scoring" below), or use up their fourth down. If they choose to go for it instead of punt, but don't make the 10-yard marker, the offense turns over the ball to its opponents at their current spot on the field. Except in special circumstances, most teams choose to punt in the "three and out" situation because it's less risky in terms of field position.
TIP: "Downs" lingo got you down? If you're confused by the announcer saying it's "Second and 4" or "First and 10," just keep in mind that the first number refers to which