Rules of flag football vary greatly, mostly depending on the sanctioning body that establishes the rules. Several regional and national bodies have developed rules for flag football. A brief overview of some key rules:
|United States Flag Football Association|
|Field specifications||Field is 53 1/3 yards wide by 80 yards long, with 10 yard endzones. Field is marked in 20 yard intervals, with a 3 yard mark from each goal line. Allowances are made for smaller or larger fields based on local geography. A goal consisting of posts 23 feet 4 inches apart (inside dimensions) with a crossbar 10 feet off the ground lies at the center of the endline behind each endzone. Pylons mark the four corners of the endzone. A down marker indicates line of scrimmage and down.|
|Officials||Four officials: Referee, Umpire, Linesman, Field Judge|
|Equipment||The ball is specified as the NFL Official Wilson Ball for men and the Official Wilson TDY Youth League Ball for women. Standard football jerseys with block numbers in a contrasting color from the jersey. Each team must wear jersey colors that contrast with each other. No padding may be worn, and shoes can bear rubber or rubber-covered cleats. Two flags worn from, but not tied to, a belt. Flags should be 3 inches wide, and of a style approved by the USFFA.|
|Players||Eight players are on the field for each team. All players and legal substitutes must wear the team uniform during the game. Free substitution is allowed during dead ball situations, though any substitute must remain on the field for a minimum of one play before leaving. Four of the eight offensive players must be on the line of scrimmage at the snap of the ball. All offensive players, including the linemen, are eligible to receive a pass.|
|Timing||Each game is 60 minutes, consisting of four quarters of fifteen minutes each. The ball is kicked off at the start of the first and third quarters. Teams switch goals at the start of the second and fourth quarters. Time is kept on a stopwatch maintained by an official OR by a visible onfield game clock. Time stops at each quarter end (though play continues after a clock stoppage until a dead ball). A "running clock" is employed, whereby the time stops ONLY after a Point After Touchdown attempt (to restart at kick off) or when a time-out is called by either team (to restart on the snap of the next play). EXCEPTION: During the last two minutes of the second and fourth quarter only, the clock shall stop for each score, or incomplete pass, or when a live ball goes out of bounds. Time out may also be called at an official's discretion for injuries or equipment problems.|
|Dead ball||A dead ball is declared for "deflagging" - the removal of one or both flags while the player is in possession of the ball. The ball carrier is down at the spot of the flag it is removed.|
|Down and distance||First downs are achieved at fixed, pre-marked 20-yard intervals on the field. A team has four downs to reach the next first down marker.|
|Blocking||Blocks may only be executed against an opponent between their waist and shoulders. Two-on-one blocks may only be executed behind the line of scrimmage. Use of extended arms and open palms is acceptable as long as the blocker is stationary or moving backwards. Holding is not allowed.|
|Scoring||Touchdowns are six points, field goals three, safeties two. On a try for Point After Touchdown(PAT), one point is awarded for a successful kick, or by a completed pass in the endzone, and two points are awarded for a running play that reaches the endzone. The location of the flag determines if a touchdown is scored, not the ball as in tackle rules. Thus, if the flag never crosses the goal line, no score occurs even if the ball does.|
|Change of possession||Possession changes after a Point After Touchdown(PAT) attempt, field goal attempt, safety, intercepted pass, punt, and after fourth down if the next first down line is not reached. Fumbles are live balls, and the defensive team may recover the fumble and retain possession.|
An important distinction is whether linemen are allowed to catch passes ("Eligible Linemen") or, as in the NFL, are not allowed to do so ("Ineligible Linemen"). Flag (and touch) football may also be divided into "contact" or "non-contact", depending on whether or not blocking is allowed; if allowed, blocking is usually restricted to the chest.
In Non-Contact football, there is no blocking, usually no linemen, and if there are linemen they can not use their hands to block an opponent. You can not get in the way of a runner, you can only attempt to grab the flag without impeding the path of the runner. Offensive players are not allowed to hand block defensive players to prevent them from grabbing the flag.
In Contact flag football, none of the rules above apply. There are linemen blocking only around chest area, no chop blocks or blocks below the waist. Defensive players can get in the path of an offensive player to attempt to grab the flag. Offensive player can hand block defensive players attempting to grab the flag.
Organized flag football leagues follow a number of sets of rules, with variants including:
The sport has a fierce amateur following and several national and international competitions each year, including the International Flag Football Federation sponsored World Cup of Flag Football featuring teams from the United States, Mexico and several other nations.
The NFL conducts their own Youth World Championship for kids 12-14 years of age. Held in different nations around the world, it is five man no contact football played between ten countries. Previous NFL Flag Football World Championships have been held in Toronto, Cologne, Mexico City, Tokyo, Vancouver and Beijing.
The NFL has also at times sanctioned "Air It Out" competitions aimed primarily at its fans in which tournament-winning teams were allowed to compete against retired NFL All-Pros.
The largest cash prize in the history of flag football ($25,000) was awarded in February 2006 by ZFOOTBALL.