Rules

1). A player's uniform consists of a jersey, trousers, helmet, shoulder pad, mouthpiece, facemask, white workout socks, and sneakers or cleats. The helmet at times may contain a listening device to communicate signals and plays. The jersey also has a number and often the player's last name.

2). Numbers on jerseys must coincide with a players’ position. For example, a quarterback can only be assigned a number between 1 and 22. Linemen are often numbers between 60 and 99. Any lineman who, for example, wishes to become an eligible receiver must report in to the referee and inform him.

3). A football field is 100 yards long by 56 yards wide. There is also an area beyond the goal line on each side of the field called the end zone which is 10 yards in length.

4). The object for each team is to move the ball across the other teams' goal line. When you achieve that, you have scored a touchdown, which results in six points. The team with the most points at the end of the game is the winner.

5). The game consists of four 15 minute periods of time known as quarters. The 1st and 2nd quarter comprise the first half, the 3rd and 4th quarters comprise the second half. At the end of the 1st and 3rd quarters the two teams switch sides of the field.

6). The game begins with one team kicking the ball to the other team. This is known as a kickoff. Each team kicks off from their own 35 yard line by either placing the ball on a tee or by having a member of the kicking team place the football on the ground and hold it while the kicker approaches the ball to kick it. Kickoffs take place:
a). At the beginning of the game (i.e. 1st quarter).
b). At the beginning of the second half (i.e.: 3rd quarter).

The decision as to which team kicks off to start the game and which team kicks off to start the second half is determined by a coin flip prior to the start of the game.

7). When the kicking team kicks the ball off to the receiving team the kicking team must then tackle the member of the receiving team with the ball (i.e.: pin the ball carrier to the ground) prior to ball carrier crossing the goal line.

8). Each team must have eleven people on the field at the start of each play. The placement of the football establishes what is known as the line of scrimmage. Members of each team may not cross the line of scrimmage until the play is initiated.

9). The team possessing the football is known as the offense. The other team is then referred to as the defense. Each offensive team has four plays (called downs) to move the football 10 yards. When an offense has moved the ball 10 yards, the offense has obtained what is called a first down which entitles them to another four plays to move the football 10 yards. This continues until either:

a). The offense moves the ball across the goal line (referred to as a touchdown). The offense scores six points
when they achieve a touchdown.
b). The offense falls short on 4th down to advance the ball 10 yards (referred to as "turning the ball over on downs").
c). The offense turns the ball over to the defense (either by way of a fumble, which is when the defense hits or grabs the football from the hands of the offensive player, or an interception, which is when the quarterback attempts to pass the ball to another offensive player typically called a "receiver" but a defensive player gets to the football first without the football falling to the ground beforehand).
d). The offense attempts to kick a field goal (obtained when a kicker kicks the football placed on the ground by
another offensive player through the uprights of the goal post, placed at the back of the end zone). The offense scores three points when they achieve a field goal.
e). The offense, realizing that their chances of obtaining a touchdown, field goal, or first down are extremely unlikely, kicks the ball to the defense. This act and formation of kicking the ball to the defense is referred to as a
punt. Unlike from a tee or a placement, the ball is "hiked" between the legs of an offensive lineman to the kicker and the kicker must then kick the ball out of his own hands. The offense must then tackle the man on the defense who receives the punt before he reaches the goal line. When that occurs, the team which was on offense is now on defense and vice versa.

10). In the act of advancing the football the offense runs one of two types of plays:
a). A running play, when an offensive player runs with the football beyond the line of scrimmage in the hope of crossing either the goal line (in case he has scored a touchdown) or beyond the yard marker which delineates where the offense has to go to obtain a first down.
b). A pass, when an offensive player (usually the quarterback) throws the ball to another member of the offensive team, usually a wide receiver, without the ball either hitting the ground or being intercepted by the defense. Assuming the offensive player catches the football in the field of play, the offensive player must then run with the football until either he/she scores a touchdown, is tackled in the field of play, is forced outside the field of play (referred to as "going out of bounds") or fumbles the football.

A pass which is caught by a member of the offensive team in the field of play is referred to as a completed pass.

A pass which is not caught and falls to the ground is referred to as an incomplete pass. An incomplete pass results in zero yards being gained on the play.

A pass which is caught but out of bounds, is an incomplete pass.

A touchdown can also be scored on a completed pass if the ball is caught by a member of the offensive team in the end zone.

If in the act of attempting a pass a member of the defense tackles the quarterback behind the line of scrimmage before he has released the football, the defense has obtained what is referred to as a "sack".

11). Common penalties: Penalties are denoted by yellow flags thrown by the referee.
Common penalties include:

a). Offsides - occurs if either the offensive team or the defensive team go across the line of scrimmage before an offensive lineman attempts to "hike" the football (i.e.: throw it between their legs) to the quarterback. This results in a five yard penalty.

b). Holding - usually occurs when a member of the offensive team grabs a member of the defensive team. Often occurs on passing plays when the offensive lineman does not want to allow members of the defense to tackle or "hit" the quarterback; results in a 10 yard penalty.

c). Illegal procedure - usually occurs when a member of the offense begins to move up field prior to the ball being hiked to quarterback. Until the ball is hiked offensive players can only move parallel to the line of scrimmage; results in a five yard penalty.

d). Pass interference - occurs when a member of the defense impedes with an offensive receiver's attempt to catch a pass. Usually occurs when the defensive player has no chance of either catching up to the football or stopping the offensive player from catching the football and scoring a touchdown. If the penalty is on the defense it results in the ball being downed where the infraction occurred except if the infraction occurred in the end zone, in which case it results in a first down and goal to go for the offense at the one yard line. If the penalty is on the offense it results in a 15 yard penalty.

e). Clip or "block in the back" - occurs on either kickoffs or punts when a member of one team (usually the team receiving the kick) blocks or hits a member of the other team in the back; results in a 15 yard penalty.

f). Intentional grounding - occurs when, in the opinion of the referee, the quarterback passes the football strictly as a means of avoiding being sacked (i.e.: tackled behind the line of scrimmage). The football must land near an eligible receiver or at least travel across the line of scrimmage; results in a 15 yard penalty from where the infraction occurred plus a loss of down. An exception to this rule is when a quarterback, immediately upon the ball being hiked to him, spikes the ball directly into the ground to stop the game clock. This usually occurs toward the end of the 1st half or the end of the game.

g). Delay of game - occurs when the offensive lineman fails to hike the ball to quarterback before 45 seconds have passed from the moment in which the previous play ended; results in a five yard penalty.

12). Extra points: After a team scores a touchdown for six points, that team then gets the ball again at the three yard line and they have the option of either:

a). Kicking the football in a manner similar to field goal in which kicker kicks the football placed on the ground by another offensive player through the uprights of the goal post, placed at the back of the end zone. This is referred to as an extra point and results in one point.

b). Advancing the ball beyond the goal line by either a running play or a passing play. This is referred to as a two point conversion and results in two points.

13). Safety: The defense scores a safety when they tackle a member of the offensive team with the football in their own end zone. This results in two points for the defense and the team which was on offense must now punt the football to the team that was on defense from their own 20 yard line.

14). Touchback: A touchback is obtained when the kicking team kicks the ball out of the other team's end zone on either a kickoff or a punt. The result is that the receiving team gets the football with 1st down and 10 yards to go on their own 20 yard line.

15). Onsides kick:  If the kicking team picks up the kicked football in the field of play before the receiving team they (and not the receiving team) will get the football with 1st down and 10 yards to go provided the football has traveled a minimum of 10 yards untouched.
When the kicking team appears to have kicked the football the bare minimum of 10 yards, they are said to have attempted an onsides kick. This usually occurs toward the end of the game when a team is losing and has just scored either a touchdown or a field goal. It is sometimes done as an element of surprise. The football must travel a minimum of 10 yards in the field of play before it can be touched by the kicking team UNLESS the receiving team touches it first.

16). Timeouts: Each team gets three timeouts per half. Another timeout, referred to as "the two minute warning" occurs on the first play that ends inside of either two minutes remaining in the first half or two minutes remaining in the game.

17). Coaches challenges: Each team gets two opportunities per game to challenge the result of a prior play. A challenge is initiated by a team's head coach throwing a red flag on to the field of play. This then prompts the referee and other officials to review the result of the prior play via replay and/or other appropriate electronic equipment.
An unsuccessful challenge results in a timeout being charged to the challenging team.
A challenge MUST be initiated prior to the start of the next play.
Officials also reserve the right to review prior plays.
Touchdowns, two-point conversions, and safeties are automatically reviewed during the final five minutes of both the 1st half and regulation (i.e.: final five minutes of the fourth quarter).

18). Keeping time during the game: The game clock stops at the end of a quarter, half, two minute warning, during a penalty, after a score of any kind, after a kickoff or a punt, after a turnover, during an official's review of the previous play, when a measurement is requested to see if a first down has been obtained, and at the end of the game.
After a player with the ball goes out of bounds, the game clock stops briefly to set the ball in the middle of the field and the game clock starts again.
After a first down is obtained, the game clock stops briefly to move the chains (used to measure 10 yards for a first down) and the game clock starts again.
The game clock continues to move after a completed pass.
The game clock stops after an incomplete pass.

19). Overtime: Overtime occurs when the score is tied at the end of the game (i.e.: at the end of the fourth quarter). The two teams continue playing until either one team scores (by way of either a touchdown, field goal, or safety) or until the equivalent of one quarter (15 minutes) have been played with neither team scoring, in which case the game results in a tie (except during the playoffs, in which case they will begin another overtime period and will continue playing until one team scores points).

The decision as to which team kicks off to start overtime and which team receives is determined by a coin flip prior to the start of the overtime.

If the receiving teams kicks a field goal without the kicking team ever having run one play on offense, the receiving team scores three points but the game continues. If however, the receiving team scores a touchdown without the kicking team ever having run one play on offense, the receiving team scores six points and the game is over with the receiving team having won.

Each team gets two timeouts during overtime.
Each team gets one coaches challenge during overtime.
Each touchdown is automatically reviewed.