Face Mask – The face mask is comprised of the protective bars on the front of the player’s helmet. Helmets with face mask are required equipment in NFL, college and high school football. A one bar face mask is the oldest type of mask, and was outlawed by the NFL in 2004. However, this rule carried a grandfather clause, allowing players to continue to wear this type of helmet for the rest of their career, if they’d been wearing it prior to the rule change. Linemen typically prefer to wear facemasks with more bars to protect themselves from other players’ hands, while quarterbacks wear smaller facemasks. The term face mask also refers to a player grabbing the bars on an opponent’s helmet. This rule violation is penalized by 5 yards if the contact is light and unintentional, and 15 yards if the face mask is used to pull the opponent’s head or force him down onto the ground.

Fair Catch – In football, a member of the team that is receiving a punt or kick, has the option to signal a fair catch. He does so by raising one arm above his head and waving it clearly from side to side. This signal must be made while the ball is still in flight. After he signals a fair catch, it is illegal for another player to interfere with the catcher or the ball. In the event that the receiver does not give the signal properly, the team can get a five yard penalty for an invalid fair catch signal. After signaling a fair catch, the player is not allowed to make contact with anyone on the other team until the ball has been touched by another player, or risk a 15 yard penalty for unsportsmanlike conduct. When an opposing team member fouls the catcher by interfering with the catch, he incurs a 15 yard penalty for his team. Should the retriever make an attempt to advance the ball after signaling fair catch, he can be penalized for delay of game.

Fair Catch Interference – a defender making contact with the receiver after he signals for a “Fair Catch” to hinder the reception, a 15 yard penalty 

Faking a Roughing – Faking a roughing is a rarely called 15 yard penalty against a kicker for trying to draw a roughing the kicker penalty against another player. An illegal act by a quarterback, kicker, or punter in which they fake being roughed by the opposition in the hopes of drawing a roughing penalty. Faking a roughing is a rarely called penalty in NFL football and results in a 15 yard penalty. A roughing penalty can be called against another player for either flagrantly running into and/or hitting the quarterback after the ball is released, or when a defender hits the quarterback in the head. Roughing is a personal foul that draws a 15 yard penalty against the offending team. In order to fake a roughing violation, a player must attempt to make it look like the opposing player has purposely run into, or hit him.

False Start – A 5 yard penalty against a member of the offense for movement before the ball is “Snapped”

Fantasy Football – a game in which players draft pretend teams from existing NFL players and then compete with other player’s teams; scoring is based on the player’s statistics

Fantasy Football– Fantasy football is a game in which players draft pretend teams from existing NFL players and then compete with other player’s teams; scoring is based on the player’s statistics. Participants are called ‘owners’ and the entity that creates the league acts as the commissioner, inviting owners to enter the league. Fantasy football leagues work under abbreviated football seasons, consisting of a draft, regular seasons and even, in some cases, playoffs. Owners accrue points through statistical analyses of their drafted players’ actual performance throughout the season. The most common type of fantasy leagues allow participants to choose players from one single football league, such as a particular college (NCAA) division or the NFL. There are several different methods that can be used to determine who wins in a fantasy football league. In some cases, the winner is simply the team that has accrued the highest number of points by the season’s end. Other leagues have head to head formats that end in playoffs.

Fantasy League – A fantasy league is a collective of fantasy football teams that compete against each other. The league may choose a winner at the end of the season based upon either the total points scored, or by means of head to head brackets and playoffs. Fantasy football is a game in which participants (called owners) create teams from existing football players and pit them against other teams in the leagues. Points are scored according to a formula that analyzes the players’ real life performance. Most leagues allow participants to draft players from only one league, such as the NCAA (college level) or the NFL. The person or entity who creates and runs the league is referred to as the commissioner, and invites participants to join in the league. Each owner participates in a draft to choose the players for his or her team.

Field Goal – a “A field goal is when a place kicker puts a held football through the uprights for three points, generally on the fourth down. Technically a field goal can be scored by either a placekick or a drop kick, although the use of drop kicks is extremely rare in the NFL today. In order to qualify as a field goal, the kick cannot be a kickoff or a free kick following a safety. While a touchdown is worth a minimum of six points, a field goal only scores three. Therefore, teams will only attempt a field goal under certain conditions, such as if it is the fourth down and the team is still fairly far from the goal, when there are only a few seconds left in the game or the half, or when a game goes into sudden death overtime and any points scored will end the game.When a team attempts a field goal, the opposing team gets into a defensive formation and tries to block it.

Field Judge – The field judge is one of the seven officials with responsibility for enforcing rules during a professional or college football game. Although they are often referred to with the generic term ‘referee’, in reality each of the officials has a specific title and job. The field judge (abbreviated as F or FJ) is an official who works downfield. He is located behind the defensive secondary on the same sideline as the line judge. The field judge is responsible for making decisions and calls near the sideline on his side of field, and judging the actions of any nearby players. Field judges may rule on such matters as pass interference, illegal blocking that occurs downfield, or incomplete passes. The field judge may have additional duties, such as serving as the official timekeeper and is also responsible for keeping count of the defensive players. In cooperation with the back judge, he determines whether or not a field goal attempt is successful.

Field of Play – In football, the field of play is the area that is marked off by the sidelines and end zones on which the game is played. The field for American football measures a total of 360 by 160 feet, with the longer sidelines and shorter boundary lines demarcating the playing area. Both endlines and sidelines are considered out of bounds during play. Each end of the field also has a goal line; these lines are situated 100 yards away from each other, and the scoring area, known as the end zone extends beyond the goal lines to the end line. The field of play is marked with yard lines (every five yards) and numbered every ten yards, from the goals up to the fifty yard line which is at mid-field. Inbound lines, also referred to as hash marks, appear at one yard intervals. Each end zone contains two upright goal posts that are connected by a crossbar.

Field Position – The position of the ball, and a given team relative to the ball, on the field during a football game is referred to as its field position. A team that starts out with the ball in a poor field position will have a harder time scoring from where they are at. Good field position is to be near the opponent’s goal line (hence, closer to scoring) and a bad field position would be one that is closer to its own goal line. Coaches teach specific strategies based upon the team’s field position. Many divide the field up into zones, with specific instructions for what types of plays to use in each different zone. Good field position is alternatively referred to as having field advantage. One of the important strategies for playing an effective football offense is to keep the ball moving to gain good field position, even when the team is not scoring.

First and Ten – Barring a penalty, this is the typical situation for the beginning of a team’s possession; first down with 10 yards to go for another first down. A down begins when the player snaps or kicks the ball, and ends when an official declares the ball or the player in possession of it, as down or when a team scores. If the player who has possession of the ball is downed, the play is ended. Every possession begins with a first down. When the line that the team needs to gain is 10 yards downfield it is called ‘first and ten’. If the team manages to move the ball past that 10 yard line, than they are making a new first down. If the ball is moved less than ten yards from the goal line, it is referred to as ‘first and goal.’

First Down – A first down is the initial play in any series in which a team has four plays to get 10 yards in order to earn another. A down begins when the player kicks or snaps the ball, and ends when and official declares the ball or the player in possession of it, as down. Each possession begins with first down. The offensive team has four downs, or plays, to move the ball at least ten yards towards the opposing team’s goal. Provided that the team is able to make the ten yards within those four downs, they are then given a new set of downs, which is referred to as getting a first down. When a team cannot move the ball at least ten yards during the four downs, the other team becomes the offense, taking possession of the ball. Many television broadcasts of games use a computer generated first down line to allow viewers to see exactly how far the team must go in order to gain a first down.

Flag Football – Flag football is another form of football, as opposed to tackle football. It is usually played by teams with 6 to 9 players each. However, instead of tackling the offensive player, the defense must pull a flag from his belt. The goal of flag football is the same, to get the ball across the opponent’s goal line in order to score. In flag football, there is no blocking and usually no linemen. In this version of the game, players are not allowed to impede the runner’s progress; instead, they must get the flag and the offensive players cannot use their hands to block a defensive player from getting the flag. Contact flag football is another form of the game that more closely resembles NFL football in that there are linemen, who block and defensive players are allowed to get in the path of offensive players to get the flag.

Flat – The flat is the area of the football field that falls between the line of scrimmage and 10 yards out into the defensive backfield, and is also within 15 yards of the sideline. This area of the field is often vacated because of the routes that other receivers use, and so it can be taken by running backs or fullbacks as a pass route, and is referred to as a flat route.When running a flat route, a receiver runs parallel to the line of scrimmage until he nears the sidelines he turns towards the quarterback to catch the pass, which should get to him before he has passed the line of scrimmage. The running back then turns upfield by the sideline and then straight downfield. This play is generally executed in one of two ways; as either an arrow or swing route. The arrow route involves a receiver taking a short direct pass, while the swing route is as described above.

Flood – to direct more offensive players to a specific zone with the hope of overwhelming the defenders responsible for covering that area and forcing them to cover more than one “Receiver” 

Formation – A formation is the arrangement that the players, both offensive and defensive, line up in before the start of a down. NFL rules require that the offense always line up in the same formation, which includes the left and right tackle, left and right guard, and a center. These five offensive positions are referred to as ‘the line’. Rules also require that there are also two Ends on the line of scrimmage, who serve as eligible receivers. Teams may choose to put additional players in, off of the line of scrimmage. Within these parameters, the offense may use many different formations such as Single Wing, Double Wing, Ace and I formations. The rules for defense formations are much less complicated, as defensive players may line up anywhere on their side of the neutral zone up until the snap. There are three basic defensive positions: defensive lineman, defensive back and linebacker. There are additional formations that may be used for punting situations.

Forward Pass – A forward pass is a throw that advances the ball down field; it must be thrown from behind the line of scrimmage. The pass consists of one offensive player throwing the football towards another downfield in the direction of the opponent's goal and is permitted only once during a scrimmage down by the offensive team before possession of the ball changes to the other team.The ball can only be caught by an eligible receiver who is a member of the offensive team. In the event that the pass is legally caught by an opposing player, it is an interception and that team has immediate possession of the ball. At that point, the player can advance the ball towards the other team’s goal. An incomplete pass occurs when no player legally catches the ball. In this case, when the ball touches the ground it is called as dead and returned to the original line of scrimmage.

Forward Progress – Forward progress is the farthest point that a ball carrier reaches before he is tackled, the point where the ball is placed regardless of where the defenders might push him back to. At the end of a play, the football is spotted at the point where the ball carrier’s forward progress was stopped. Forward progress determines the location that the ball is declared dead. When there is a cluster of players, it can be difficult for officials to determine the furthest point that the ball landed at. The wing official makes a ruling as to the position of the ball, although the game’s referee may step in to adjust if necessary. There is some controversy surrounding the forward progress rule, as it allows the offense to gain yardage, even if the defense is able to push him back beyond the farthest point that he had previously reached.

Foul – In football, a foul is any illegal maneuver. A foul may also be referred to as a penalty, and by definition incurs a specific sanction against a player and/or team as a result of this violation of rules. The majority of fouls result in 5, 10 or 15 yard penalties, in which the ball is moved that amount in the direction of the offending team’s end zone. A few penalties carry other sanctions, including loss of a down for the offending team, or an automatic safety. Some of the most commonly seen fouls include: offsides (being out of bounds), false start (moving out of position prior to the ball snap), holding, delay of game, pass interference (getting in the path of an eligible receiver getting ready to catch), face mask (grabbing an opponent’s helmet face mask) and illegal blocks such as clipping or chop blocking.

Franchise – A franchise is an NFL (National Football League) professional football team. The NFL is the largest professional American football league in the world, and is run by its members as a non-profit organization. Currently there are thirty two franchises in the NFL. These teams are divided into both conferences and geographic regions. The two conferences that comprise the NFL are the AFC (American Football Conference) and the NFC (National Football Conference). The majority of the NFL franchises are located in the Eastern half of the U.S. Each individual franchise, or team, is allowed to list up to 53 players on its roster at any time. There are a few now-defunct franchises that are no longer part of the NFL, as well as many that remain a part of the organization but relocate to other cities. Franchises may be owned by private individuals or other legal entities.

Franchise Player – A title given a player to keep him from leaving the team as a free agent. In order to qualify for this designation, a player must be paid the average salary of the top five players in his position. NFL rules allow teams to designate only one player as their franchise player, but in return that player is paid a top salary, equal to either the average for the top five players in the league, or 120% of his previous year’s salary, whichever is higher. Not all teams choose to use the franchise player option. For example, in 2008, 12 of 32 teams. When a player is tagged as the franchise player for a team, it is for one year only but can be renewed. If not renewed, the player is then an unrestricted free agent. Many teams use the franchise player option to negotiate, and in some cases get a long-term contract with him.

Free Agent – A free agent is a player who is not under any contractual obligation to his current team, and is free to sign a contract with whatever team he desires. The NFL recognizes three different kinds of free agents. Unrestricted Free Agents (UFAs) are players that have completed four or more seasons and have an expired contract. UFAs are allowed to sign on with any club they choose. Restricted Free Agents (RFA) must have completed three seasons of football and have an expired contract. These players are allowed to bargain with all of the clubs until late April, after which the rights to the player’s roster goes to the other team. Exclusive Rights Free Agents (ERFA) are players with 0-2 years of play, who have expired contract. ERFAs are not able to negotiate a contract with another team, but may choose to sit out the season instead.

Free Agency – Free agency refers to the period of time when a player is no longer under contract and can be signed by any team. A free agent is a player whose contract with a specific team has expired, and is eligible to sign with another team, if they desire. When a player enters into free agency, he is in a pool of free agents that teams may choose from. Being a free agent gives talented players an excellent negotiating position. There are three different levels of free agency within the NFL: restricted free agency, Exclusive-Rights free agency and Unrestricted Free Agency. Players who have completed three seasons and have no contract are Restricted Free Agents, and are allowed to negotiate with any team until a certain date, after which the rights go their original club. Unrestricted free agency is given to players who have completed four or more seasons. Exclusive rights free agency is for players with up to two seasons of play; these players have limited negotiating rights and must sign on with their own club or stay out for a season.

Free Kick – A free kick is a kick that is used to restart a football game, and may be either a kickoff or a punt following a safety. At the start of each half, and should the game go into overtime, a kickoff begins play.To begin the game, the visiting team’s captain gets to call a coin toss and the winning team chooses whether to receive the ball in the first or the second half. During a free kick, the ball is situated in between the kicking team’s own goal line and the 30 yard line (for NFL football). It can be fielded by the receiving team from the moment that his has been kicked, but the kicking team cannot intercept it until it has either traveled at least ten yards or been touched by one of the defensive players. After a safety occurs, the team that gave up points gets to kick off to the other team, and may choose to punt, drop kick or kick from a teammate.

Free Safety – A free safety (FS) is the defending player who lines up deepest in the secondary in the middle of the field. The FS is one of two types of safeties, the other being a strong safety (SS). The duties of a free safety will depend upon the type of formation that the defense chooses to play in. For the most part, FS are smaller and faster players than the strong safeties. The primary responsibility of the free safety is to close in on the receiver by the time the ball has reached him. In some cases, the free safety may also be called upon to blitz, or to cover certain receivers on play action passes. The FS and SS may divide up their duties by zone or by working on run support versus pass resort. Dividing the field into two zones, basically a right half and a left half, is a commonly used form of defense called the Cover-2.

Freeze – See “Controlling the Clock”

Front Four – a defensive line “Formation” of two “Ends” and two “Tackles”

Front Seven – the “Linemen” and “Linebackers”

Fullback – A fullback is a back who generally lines up in front of the half back and in addition to occasionally carrying the ball, he’s generally lead blocker for the half back on running plays or defends the quarterback on passing plays. Not all teams use fullbacks , opting instead to have two tight end sets. The position has changed through the years, and although a fullback is a ‘back’ in name, at this stage he serves as more blocker than runner. A fullback will also share pass-catching duties on occasions. Most fullbacks are heavier and larger players, and aren’t noted so much for speed and agility, but rather their ability to shake off tackles and keep going. Fullbacks are used primarily for breaking through tight defensive formations and in short-yardage situations. They are also called out for screen passes.

Fumble – A fumble occurs when the player who is carrying a ball loses possession of it during a play. Any act that is not passing, kicking or successfully handing the ball to another player means that there is a loss possession. A fumble can be accidental, or one that is forced by a defense player who is able to grab, punch or butt the ball out of the other player’s hands. Generally, when a ball is fumbled, either team may recover it and continue to advance. NFL rules state that if the fumble occurs after the 2 minute warning , the ball is ruled dead at the spot if it bounces backwards; if it bounces forward it will be spotted at the point of the fumble. A fumble contrasts with a muff, which occurs when a player ends up dropping a ball that he doesn’t currently have possession of. This can happen if, for example, he is attempting to catch a lateral pass.