American football grew out of rugby and soccer, two older sports. The first college football game was played between Rutgers and Princeton on November 6, 1869, and it used modified London Football Association rules. You may have heard that football has always been played with the same rules, but it has not. The first Harvard-Yale game was played on November 13, 1875, and at the Massasoit convention in 1876, the first rules for American football were written. Walter Camp, who played at Yale, became known as the father of American football, and he invented the line of scrimmage and the system of downs. In 1890 Yale introduced cheerleaders at a football game, a first in college sports.

A football is not round, and it is covered in tan leather, and a football weighs 14 to 15 ounces. Each football team has 11 players on the field at one time, and the scoring has changed along the way. In 1892 a touchdown counted four points, and a touchdown used to be worth five points before it was increased to six. Today a team scores a touchdown by getting the ball across the other team's goal line, and after a touchdown, a team can try to score one or two more points. A field goal is worth three points, and a safety is worth two points.

As of November 2026, an NFL field is a rectangle 360 feet long and 160 feet wide, and a player who touches a sideline is out of bounds. A football game lasts 60 minutes, divided into four quarters of 15 minutes each. At halftime, between the second and third quarters, play stops and the teams leave the field, and in the NFL the game stops automatically at the two-minute warning in the second and fourth quarters. Football players wear helmets that have a face mask, and they must wear shoulder pads, knee pads and thigh pads. In the NFL a player's jersey number shows what position he plays, and every football player wears a number on the front and back of his jersey.

The center snaps the ball between his legs to the quarterback to start each play. The quarterback leads the offense: he tells his teammates which plays to run. A running back is the main ball carrier, and he can run with the ball or catch a forward pass. Wide receivers line up near the sidelines, run downfield and catch passes from the quarterback, and a tight end lines up at the end of the offensive line, blocking on runs or catching passes. A forward pass is thrown by an offensive player, usually the quarterback, from behind the line of scrimmage toward an eligible receiver, and a team may throw a sideways or backward pass, called a lateral, as many times as it likes on a play.

The team with the ball gets four downs, or tries, to move the ball 10 yards, and officials use a 10-yard chain on two rods to see whether a team has earned a first down. As of November 2026, a 40-second play clock starts when a play ends, and the team that does not snap the ball in time gets a five-yard penalty. The neutral zone is the space between the two teams' lines before the snap, and neither team may enter it until the ball is snapped. A player is offside when part of his body is in the neutral zone before the ball is put in play, and a flag thrown by an official shows that a penalty has been called.

A punt is a kick in which the kicker drops the ball and kicks it before it hits the ground. A receiver who signals a fair catch by waving one arm cannot run with the ball, and the other team may not tackle him. A fumble happens when a player with the ball loses it, and either team can recover it. A kickoff starts each half and follows each touchdown try or successful field goal. As of November 2026, the kicking team kicks from its own 35-yard line on a kickoff.

The pros came later. The NCAA grew out of a 1905 meeting of colleges that wanted to reform football's playing rules. The American Professional Football Association changed its name to the National Football League, and William (Pudge) Heffelfinger was paid $500 to play in a football game for the Allegheny Athletic Association. The NFL, which long had followed the rules of college football, made a number of significant changes from the college game for the first time. In 1966 the NFL and the American Football League agreed to merge and to play an annual contest between their champions in the meantime. Lamar Hunt, who owned the Kansas City Chiefs, suggested the name Super Bowl, inspired by a bouncy toy called the Super Ball. Roman numerals were first used for Super Bowl V, and the Pro Football Hall of Fame was dedicated at Canton, Ohio, on September 7, 1963.

Words to know

• scrimmage: starting line
• lateral: sideways pass
• offside: too far forward
• merge: join together
• convention: big meeting