American football

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For information on other sports known as "football", see the football article.
For the Chicago-based indie rock band, see American Football (band).
The ball used in American football has a pointed oval shape, and usually has a large set of stitches along one side.
The ball used in American football has a pointed oval shape, and usually has a large set of stitches along one side.

American football, known in the United States and Canada simply as football, is a competitive team sport. The object of the game is to advance the football towards the opposing team's end zone and score points. The ball can be advanced by carrying the ball, or by throwing or handing it from one teammate to the other. Points can be scored in a variety of ways, including carrying the ball over the goal line, throwing the ball to another player past the goal line or placekicking it through the goal posts. The winner is the team with the most points when the time expires.

Outside of the United States and Canada, the sport is usually referred to as American football to differentiate it from other football games, especially association football and rugby football. American football evolved as a separate sport from rugby football in the late 19th century. Arena football is a variant of American football.



Since the 1960s, football has surpassed baseball as the most popular spectator sport in the United States. The 32-team National Football League (NFL) is the most popular and only major professional American football league. Its championship game, the Super Bowl, is watched by nearly half of US television households, and is also televised in over 150 other countries. Super Bowl Sunday has become an annual ritual in late January or early February.

The NFL also operates a developmental league, NFL Europe, with 6 teams based in European cities.

A Colorado State University player runs with the ball as an Air Force Academy player tries to thwart his progress.
A Colorado State University player runs with the ball as an Air Force Academy player tries to thwart his progress.

College football is also extremely popular throughout the U.S., especially in markets not served by an NFL team. Several college football stadiums seat more than 100,000 fans -- which regularly sell out. Even high school football games can attract five-figure crowds, especially in hotbeds like Western Pennsylvania, Ohio, Florida, Texas and Georgia. The weekly autumn ritual of college and high-school football -- which includes marching bands, cheerleaders and parties -- is an important part of the culture in much of smalltown America.

Football is also played recreationally by amateur club and youth teams (e.g., the Pop Warner little-league programs). There are also many "semi-pro" teams in leagues where the players are paid to play, but at a small enough salary that they generally must also hold a full-time job.

Organized football is played almost exclusively by men and boys.

The rules of American football

See also: American football rules

Objective: Like most other games of football, the object of American football is to advance the ball towards the opponent's end of the field and score more points than the opposing team within a set time limit.

Field and players

The numbers on the field indicate the number of yards to the nearest end zone.
The numbers on the field indicate the number of yards to the nearest end zone.

The American football field is often called the gridiron because the markings on the field resemble that type of grill that can be used to cook food over a fire. The game is played on a rectangular field 120 yards (110 meters) long by 53-1/3 yards (49 meters) wide. The longer boundary lines are sidelines, while the shorter boundary lines are end lines. Near each end of the field is a goal line; they are 100 yards (91 meters) apart. A scoring area called an end zone extends 10 yards (9.1 meters) beyond each goal line to each end line.

Yard lines cross the field every 5 yards (4.55 meters), and are numbered from each goal line to the 50-yard (45.5-meter) line, or midfield (similar to a typical rugby league field). Two rows of lines, known as hash marks parallel the side lines near the middle of the field. All plays start with the ball on or between the hash marks.

At the back of each end zone are two goal posts (also called uprights) that are 18.5 feet (5.6 meters) apart. The posts are connected by a crossbar 10 feet (3 meters) from the ground. Successful kicks must go above the crossbar and between the uprights. (At many fields the uprights and crossbar are attached by a curved bar to a post outside the field of play, to reduce the chance of players running into the supports.)

Each team has 11 players on the field at a time. However, teams may substitute for any or all of their players between plays. As a result, players have very specialized roles, and almost all of the 53 players on an NFL team will play in any given game. Thus, teams are divided into three separate units: the offense, the defense and the special teams (see below).

Game duration

A standard football game consists of four 15-minute (typically 12 minutes in high school football) periods (called quarters), with an intermission (called halftime) after the second quarter. The clock stops after certain plays; therefore, a game can last considerably longer (often more than three hours in real time). If an NFL game is tied after four quarters, the teams play up to another 15 minutes. The first team that scores wins; if neither team scores, the game is a tie. College overtime rules are more complicated and are described at Overtime (sport).

Advancing the ball

Advancing the ball in American football resembles the six-tackle rule and the play-the-ball in rugby league football. The team that takes possession of the ball (the offense) has four attempts, called downs, to advance the ball 10 yards towards their opponent's (the defense's) end zone. When the offense gains 10 yards, it gets a first down, or another set of four downs to gain 10 yards. If the offense fails to gain a first down, it loses possession of the ball.

Except at the beginning of halves and after scores (see Kickoffs and free kicks below), the ball is always put into play by a snap. All players line up facing each other at the line of scrimmage (the position on the field where the play begins). One offensive player, the center, then passes (or "snaps") the ball between his legs to a teammate, usually the quarterback.

Players can then advance the ball in two ways:

  • By running with the ball, also known as rushing.
  • By throwing the ball to a teammate, known as passing. The forward pass is a key factor distinguishing American and Canadian football from other football sports. The offense can throw the ball forward only once on a play and only from behind the line of scrimmage. The ball can be thrown sideways or backwards at any time. This type of pass is known as a lateral and is much rarer in American football than in rugby league or rugby union.

A play or down ends, and the ball becomes dead, after any of the following:

  • The player with the ball is tackled to the ground by a member of the opposing team, or has his forward progress stopped (as determined by an official).
  • A forward pass flies out of bounds or touches the ground before it is caught. This is known as an incomplete pass. The ball is returned to the original line of scrimmage for the next down.
  • The ball or the player with the ball goes beyond the dimensions of the field (out of bounds).
  • A team scores.

Often an official will blow a whistle to notify all players that the play is over.

The ball may also change position as a result of penalties. These penalties may be incurred by either the offensive or defensive team. Generally, penalties involve a loss of yardage for the penalized team, and sometimes an automatic first down. Field officials signal that a penalty has been incurred by throwing a yellow flag onto the field near the site of the penalty, while the play continues. When the play ends, the referee names the penalty and the consequences thereof.

Changes of possession

The offense maintains possession of the ball unless one of the following things happens:

  • The team fails to get a first down, that is, move the ball forward at least 10 yards in four downs. The defensive team takes over the ball at the spot where the play ends.
  • The offense scores a touchdown or field goal. The team that scored then kicks off the ball to the other team. (See Scoring and Kickoffs below.)
  • The offense punts the ball to the defense. A punt is a kick in which a player drops the ball and kicks it before it hits the ground. Punts are nearly always made on fourth down, when the offensive team does not want to risk giving up the ball to the other team at its current spot on the field (through a failed attempt to make a first down) and feels it is too far from the other team's goal posts to kick a field goal.
  • A defensive player catches a forward pass. This is called an interception, and the player who makes the interception can run with the ball until tackled or forced out of bounds.
  • An offensive player drops the ball (a fumble), and a defensive player picks it up. As with interceptions, a player recovering a fumble can run with the ball until tackled or forced out of bounds. Lost fumbles and interceptions are together known as turnovers.
  • The offensive team misses a field goal attempt. The defensive team gets the ball at the spot where the previous play began (or, in the NFL, at the spot of the kick). If the unsuccessful kick was attempted from very close to the end zone, the other team gets the ball at its own 20-yard line (that is, 20 yards from the end zone).
  • An offensive player is tackled or forced out of bounds in his own end zone. This rare occurrence is called a safety. (See Scoring below.)


A team scores points by the following plays:

  • A touchdown is worth 6 points. A touchdown is scored when a player runs the ball into or catches a pass in his opponent's end zone.
    • After a touchdown, the scoring team attempts a conversion. The ball is placed at the other team's 3-yard-line (the 2-yard-line in the NFL). The team can attempt to kick it over the crossbar and through the goal posts for 1 point (an extra point), or run or pass it into the end zone for 2 points (a two-point conversion). The extra point is usually attempted because it is significantly easier to achieve.
  • A field goal is worth 3 points, and it is scored by kicking the ball over the crossbar and through the goal posts. Field goals must be placekicked, that is, kicked when the ball is held vertically against the ground by a teammate. A field goal is usually attempted on fourth down instead of a punt when the ball is close to the goal line.
  • A safety is worth 2 points. A safety is scored when a player has possession of the ball in his own end zone and gets tackled there or fumbles the ball out of his own end zone. This rare event is generally caused by the line of scrimmage being very close to the offense's own endzone, meaning that part of the play might occur in the endzone itself. Teams generally try to avoid risking a safety in this situation by using plays that do not require the ball to be carried back into their own endzone (avoiding for example a pass play where the quarterback must retreat into the endzone to have room to throw the ball). Certain penalties by the offense occurring in the end zone also result in a safety.

Kickoffs and free kicks

Each half begins with a kickoff. Teams also kick off after scoring touchdowns and field goals. The ball is kicked from a kicking tee, which is made from one's own 30-yard line in the NFL and from the 35-yard line in college football. The other team's kick returner tries to catch the ball and advance it as far as possible. Where he is stopped is the point where the offense will begin its drive, or series of offensive plays. If the kick returner catches the ball in his own end zone, he can either run with the ball, or elect for a touchback by kneeling in the end zone. The receiving team can then start its offensive drive from its own 20-yard line. A touchback can also occur when the kick goes out of the end zone. Punts and turnovers in the end zone can also end in touchbacks.

After safeties, there is a free kick instead of a kickoff. A free kick is made from a team's own 20-yard-line and can be punted or placekicked.

The players

As noted above, most football players have highly specialized roles. At the college and NFL levels, most play only offense or only defense.


  • The offensive line (OL) consists of five players (two offensive tackles (OT), two guards (G), and a center (C)) whose job is to protect the passer and clear the way for runners by blocking members of the defense. All plays begin with the center handing the ball backwards between his legs, or snapping it, to a teammate, usually the quarterback.
  • The quarterback (QB) receives the ball on most plays. He then hands or tosses it to a running back, throws it to a receiver or runs with it himself.
  • Running backs (RB) line up behind or beside the QB and specialize in rushing with the ball. They also block, catch passes and, on rare occasions, pass the ball to others. There are two main kinds of running backs: fullbacks (FB), who usually block, and halfbacks or tailbacks, who are more likely to carry the ball.
  • Wide receivers (WR) line up near the sidelines. They specialize in catching passes.
  • Tight ends (TE) line up outside the offensive line. They can either play like wide receivers (try to catch passes) or like offensive linemen (protect the QB or create spaces for runners).

Not all of these types of players will be in on every offensive play. Teams can vary the number of wide receivers, tight ends and running backs on the field at one time.


  • The defensive line (DL) consists of three to five players (two defensive ends, one or two defensive tackles (DT), and possibly one nose guard (DT)) who line up across from the offensive line. They try to tackle the running backs before they can gain yardage or the quarterback before he can throw a pass.
  • At least four players line up as defensive backs (DB). They may be cornerbacks (CB), free safeties (FS), or strong safeties (SS). They cover the receivers and try to stop pass completions. They occasionally rush the quarterback.
  • The other players on the defense are known as linebackers (LB). They line up between the defensive line and backs and may either rush the quarterback or cover receivers and/or running backs.

Special teams

The units of players who handle kicking plays are known as special teams. Special-teams players include the punter (P), who handles punts, and the kicker or placekicker (K or PK), who kicks off and attempts field goals and extra points. Field goal and extra point attempts also require a holder who receives the ball from the center and holds it in a position that allows the kicker to easily kick the ball.

Basic football strategy

Main article: American-football strategy

To many fans, the chief draw of football is the chess game that goes on between the two coaching staffs. Each team has a playbook of dozens to hundreds of plays, or directions for what the players should do on a down. Some plays are very safe; they are very likely to get a few yards, but not much more than that. Other plays have the potential for long gains but a greater risk of a loss of yardage or a turnover.

Generally speaking, rushing plays are less risky than passing plays. However, there are relatively safe passing plays and risky running plays. To fool the other team, there are passing plays designed to look like running plays and vice versa. There are many trick or gadget plays, such as when a team lines up like it is going to kick and then tries to run or pass for a first down. Such high-risk plays are a great thrill to the fans when they work. However, they can spell disaster if the opposing team realizes the deception and acts accordingly.

It has been said that football is the closest sport that strategically resembles real war, which may explain why it is by far the most popular sport in the American military. In fact, the Army, Navy and Air Force all have football teams of their own that participate in the collegiate leagues. The Army and Navy have a particularly historic rivalry.

Development of the game

For more information see the article: History of American football.

Both American football and soccer have their origins in varieties of football played in the United Kingdom in the mid-19th century, and American football is directly descended from rugby football.

Rugby was first introduced to North America in Canada, brought by the British Army garrison in Montreal which played a series of games with McGill University. Both Canadian and American football evolved from this point. For an in-depth overview of the differences and similarities of Canadian football and American football see: Comparison of Canadian and American football

American colleges spearheaded the growth of football. The first inter-collegiate football game was played between Rutgers and Princeton Universities on November 6, 1869. The game was won by Rutgers (6-4) although "The game, which bore little resemblance to its modern-day counterpart, was played with two teams of 25 men each under rugby-like rules, but like modern football, it was “replete with surprise, strategy, prodigies of determination, and physical prowess,” to use the words of one of the Rutgers players." - Rutgers Football

American football in its current form grew out of a series of three games between Harvard University and McGill University of Montreal in 1874. McGill played rugby football while Harvard played the Boston Game, which was closer to soccer. As often happened in those days of far from universal rules, the teams alternated rules so that both would have a fair chance. The Harvard players liked having the opportunity to run with the ball, and in 1875 persuaded Yale University to adopt rugby rules for their annual game. In 1876 Yale, Harvard, Princeton, and Columbia formed the Intercollegiate Football Association, which used the rugby code, except for a slight difference in scoring.

In 1880 Walter Camp introduced the scrimmage in place of the rugby scrum. In 1882 the system of downs was introduced to thwart Princeton's and Yale's strategy of controlling the ball without trying to score. In 1883 the number of players was reduced, at Camp's urging, to eleven, and Camp introduced the soon standard arrangement of a seven-man offensive line with a quarterback, two halfbacks, and a fullback.

On September 3, 1895 the first professional football game was played, in Latrobe, Pennsylvania, between the Latrobe YMCA and the Jeannette Athletic Club. (Latrobe won the contest 12-0.).

By the 1890s interlocking offensive formations such as the flying wedge and the practice of teammates physically dragging ball-carrying players forward had made the game extremely dangerous. Despite restrictions on the flying wedge and other precautions, in 1905 eighteen players were killed in games. President Theodore Roosevelt informed the universities that the game must be made safer. To force them to respond to his concerns, he threatened to pressure Congress to make playing football a federal crime.

In 1906, two rival organizing bodies, the Intercollegiate Rules Committee and the Intercollegiate Athletic Association, met in New York; eventually they agreed on several new rules intended to make the game safer, among them the addition of a neutral zone between the scrimmage lines and a requirement that at least six players from each team line up on them. The most far-reaching innovation they considered, though, was the legalization of the forward pass. This was very controversial at the time, much derided by purists. As an alternative means of opening out the play, Walter Camp would have preferred widening the field; but representatives from Harvard pointed to recently constructed Harvard Stadium, which could not be widened, and the forward pass was adopted; it has come to shape the whole history of American football, as opposed to its cousins around the world.

In 1910, after further deaths, interlocking formations were finally outlawed; and in 1912 the field was changed to its current size, the value of a touchdown increased to 6 points, and a fourth down added to each possession. The game had achieved its modern form.

Problems in Football

For more information see the article: Issues in American Football.

Injuries are more common in American football than in many other sports, although rule changes made in the past 90 years (for instance, the elimination of "horse-collar tackles") have gradually lowered the rates of injuries. In addition, protective equipment has become better - for example, the optional leather helmets introduced during the 1890s have been replaced (in several stages) by high-tech padded metal or plastic helmets with bars protecting the face.

More recently, the use of steroids and the extent thereof has become an object of debate in professional, college, and even high school football leagues. (Pop Warner leagues appear to so far be immune to questions of whether players "juice up" or not.)

Another problem with football is that it is an expensive sport. The specialized helmets, uniforms, and pads can cost hundreds of dollars. There is a widespread perception that football teams based in schools and public recreational leagues consume far more than their fair share of the sports budget, although sales of tickets to college (and to some extent high school) football games often make it a revenue-producing sport.

Professional, college, and other leagues

Football is played at a number of levels in the United States and abroad. These include the following:

A spring professional football league, the All American Football League, is presently being formed.

The descriptions in this article are based primarily on the current rules of the National Football League (NFL, 1920-present). Differences with college rules will be noted. Professional, college, high school, and amateur rules are similar.

Professional leagues that no longer exist include the World Football League (WFL, 1974-75), the United States Football League (USFL, 1983-1985), the XFL (XFL, 2001), the All-America Football Conference (1946-1949) (2 teams are now in the NFL), the World League of American Football (WLAF, 1991-1993 — now NFL Europe), and, the American Football League (AFL, 1960-1969). Only the AFL survives, as it merged with the NFL in 1970 and now exists (mostly) as the AFC.


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