There are basically five different ways to score points in football: a touchdown, a field goal, a safety, a two-point conversion, and an extra point. The most valuable scoring play in football is the touchdown, which is worth six points. A touchdown is scored when the player in possession of the football crosses the opposing team's goal line. In order for a touchdown to be scored, the player's body does not need to cross the goal line. If any part of the football even touches the "plane" of the goal line -- an imaginary plane stretching upward infinitely from the front edge of the line -- the play is ruled a touchdown.

A touchdown in football comes with the opportunity to score more points. After a touchdown, the scoring team has the option of attempting an extra point or a two-point conversion. An extra point involves a field-goal type place kick, with the line of scrimmage near the 2-yard line.

A converted kick -- one that sails between the uprights -- is worth one point. A two-point conversion is an offensive play that is run from the same line of scrimmage as an extra point. To receive the two points, the offensive team must cross the goal line with possession of the football.

A field goal in football is worth three points, and it is scored by place-kicking the ball through the uprights. A field goal can be attempted on any offensive play, but attempts are usually reserved for 4th down. It is only common to attempt a field goal earlier than 4th down when the offensive team is trailing by three points or less and there is not enough time on the clock to safely attempt to score a touchdown while still leaving time for a field goal attempt.

A safety is the least common scoring play in football. It occurs when the offensive team is tackled in its own end zone, when a fumbled ball goes out of bounds in the offensive team's end zone, or when the offensive team commits a holding penalty or intentional grounding penalty in its own end zone. The play results in two points awarded to the defensive team, and the offensive team must then kick the ball off to the defensive team. Kickoffs are held after every scoring play, but a safety is the only scoring play in football after which the scoring team receives the kickoff.

If a player fields a kickoff, intercepts a pass or recovers a fumble while in his own end zone, and is tackled or goes out of bounds before leaving the end zone, there is no safety. If the player gains possession outside the end zone, then retreats to the end zone of his own accord and is tackled or goes out of bounds there, a safety is scored.