In gridiron football, not all players on offense are entitled to receive a forward pass: only an eligible pass receiver may legally catch a forward pass, and only an eligible receiver may advance beyond the neutral zone if a forward pass crosses into the neutral zone. If the pass is received by a non-eligible receiver, it is "illegal touching". If an ineligible receiver is beyond the neutral zone when a forward pass crossing the neutral zone is thrown, a foul of "ineligible receiver downfield" is called. Each league has slightly different rules regarding who is considered an eligible receiver.
In gridiron football, a lineman is a player who specializes in play at the line of scrimmage. The linemen of the team currently in possession of the ball are the offensive line, while linemen on the opposing team are the defensive line. A number of NFL rules specifically address restrictions and requirements for the offensive line, whose job is to help protect the quarterback from getting sacked for a loss, or worse, fumbling. The defensive line is covered by the same rules that apply to all defensive players. Linemen are usually the largest players on the field in both height and weight, since their positions usually require less running and more strength than skill positions.
A cornerback (CB) is a member of the defensive backfield or secondary in gridiron football. Cornerbacks cover receivers most of the time, but also blitz and defend against such offensive running plays as sweeps and reverses. They create turnovers through hard tackles, interceptions, and deflecting forward passes.
The tight end (TE) is an offensive position in American football, arena football, and Canadian football. It is a hybrid that combines the characteristics and roles of both an offensive lineman and a receiver. As part of the receiver corps, they play inside the flanks (tight), contrasted with the split end who plays outside the flanks (wide). Like offensive linemen, they are usually lined up on the offensive line and are large enough to be effective blockers. On the other hand, unlike offensive linemen, they are eligible receivers and potent weapons in a team's offensive schemes. A good tight end is designed to be a mismatch in one of two ways- due to their larger size to a regular receiver an opposing team may allocate a defensive lineman to block a tight end for run plays, but that lineman would be unable to keep up with a tight end on a passing play. Conversely, an opposing team may allocate a smaller and faster safety or cornerback to guard a tight end in case of a pass play, but then that safety will be in danger of being overpowered by the tight end in a run play.
Strategy is a major part of American football.
American football positions have slowly evolved over the history of the sport. From its origins in early rugby football to the modern game, the names and roles of various positions have changed greatly, some positions no longer exist, and others have been created to fill new roles.
A formation in American football refers to the position players line up in before the start of a down. There are both offensive and defensive formations and there are many formations in both categories. Sometimes, formations are referred to as packages.
In sports, a starting lineup is an official list of the set of players who will participate in the event when the game begins. The players in the starting lineup are commonly referred to as starters, whereas the others are substitutes or bench players.
A sweep is an outside running play in American football where a running back takes a pitch or handoff from the quarterback and starts running parallel to the line of scrimmage, allowing for the offensive linemen and fullback to get in front of him to block defenders before he turns upfield. The play is run farther outside than an off tackle play. Variants of the sweep involve the quarterback or a wide receiver running with the ball, rather than a running back. When a wide receiver runs with the ball, it is known as a jet sweep.
A trick play, also known as a gadget play, gimmick play or trickeration, is a play in gridiron football that uses deception and unorthodox tactics to fool the opposing team. A trick play is often risky, offering the potential for a large gain or a touchdown if it is successful, but with the chance of a significant loss of yards or a turnover if not. Trick plays are rarely used not only because of the riskiness, but also to maintain the element of surprise for when they are used.
In American football, the specific role that a player takes on the field is referred to as their "position". Under the modern rules of American football, both teams are allowed 11 players on the field at one time and have "unlimited free substitutions", meaning that they may change any number of players during any "dead ball" situation. This has resulted in the development of three task-specific "platoons" of players within any single team: the offense, the defense, and "special teams". Within these three separate "platoons", various positions exist depending on the jobs that the players are doing.
Slotback, also called S-back or A-back, is a position in gridiron football. The "slot" is the area between the offensive tackle and the wide receiver. A player who lines up between those two players and behind the line of scrimmage fills that "slot".
Safety (S), historically known as a safetyman, is a position in gridiron football on the defense. The safeties are defensive backs who line up ten to fifteen yards from the line of scrimmage. There are two variations of the position: the free safety (FS) and the strong safety (SS). Their duties depend on the defensive scheme. The defensive responsibilities of the safety and cornerback usually involve pass coverage towards the middle and sidelines of the field. While American (11-player) formations generally use two safeties, Canadian (12-player) formations generally have one safety and two defensive halfbacks, a position not used in the American game.
In American football, a play is a close-to-the-ground plan of action or strategy used to move the ball down the field. A play begins at either the snap from the center or at kickoff. Most commonly, plays occur at the snap during a down. These plays range from basic to very intricate. Football players keep a record of these plays in a playbook.
The following terms are used in American football, both conventional and indoor. Some of these terms are also in use in Canadian football; for a list of terms unique to that code, see Glossary of Canadian football.
In American football, a back is a player who plays off of the line of scrimmage. Historically, the term "back" was used to describe multiple positions on offense and defense, although more descriptive and specific position naming is now common. Thus, "back" can refer to positions including:
A play calling system in American football is the specific language and methods used to call offensive plays.
Players in the National Football League (NFL) wear uniform numbers between 0 and 99, with no two players on a team able to wear the same number outside of the offseason. Rules exist which tie a player's number to a specific range of numbers for their primary position. Additionally, rules exist which limit who may handle the ball on offense: generally players who are designated as offensive linemen, who wear numbers 50–79, are not allowed to handle the ball during a play from scrimmage, though they are allowed to do so if they report to the referee as playing out of position for a tackle-eligible play, if they pick up a fumble, or if they catch a deflected pass.
A route is a pattern or path that a receiver in gridiron football runs to get open for a forward pass. Routes are usually run by wide receivers, running backs and tight ends, but other positions can act as a receiver given the play.
