Positions in American Football: The Rulebook Only Recognises Two of Them
TL;DR
American football has 22 conventional positions, but the rulebook does not name most of them. What the rules actually govern is formation and eligibility: seven players must be on the line of scrimmage, only the two on the ends of that line may catch a pass, and everyone in the backfield may. Jersey numbers carry the force of law — 50 to 79 makes you ineligible unless you report otherwise to the referee.
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The positions, as everyone uses them
| Offence | Defence |
|---|---|
| Quarterback (QB) | Defensive tackle (DT) |
| Running back (RB) | Defensive end (DE) |
| Fullback (FB) | Linebacker (LB) |
| Wide receiver (WR) | Cornerback (CB) |
| Tight end (TE) | Free safety (FS) |
| Centre (C) | Strong safety (SS) |
| Offensive guard (OG) | |
| Offensive tackle (OT) |
Special teams: kicker, punter, long snapper, holder, returner, gunner.
That is the vocabulary. Now the part that is usually left out.
The rulebook does not know what a quarterback is
Search the rules for a definition of “quarterback”, “running back” or “wide receiver” and you will not find one that governs anything. These are coaching conventions, not legal categories.
What the rules actually regulate is narrower and stranger:
Where you stand. Seven of the eleven offensive players must be on the line of scrimmage. The other four are backs.
Whether you may catch a pass. Of the seven on the line, only the two at the ends are eligible. The interior five are not. Every back is eligible.
What number you wear. Numbers 50 to 79 are ineligible numbers.
A team fields the same eleven players whatever it calls them. The rules care only about the alignment those players take and the numbers on their backs.
Up to six may catch the ball
Count it out. Seven on the line, of whom two ends are eligible. Four in the backfield, all eligible. That is six eligible receivers, the NFL maximum.
The other five — the interior linemen — cannot receive a forward pass, and cannot be downfield when one is thrown. That is the ineligible receiver downfield penalty, and it is the rule that stops all eleven players simply running routes.
One exception is worth knowing. A quarterback taking the snap from directly under centre is not an eligible receiver. Lined up in shotgun, the same player is a back like any other and becomes eligible. Same person, same jersey, different alignment, different legal status.
That is the clearest possible demonstration of the point: eligibility attaches to where you are standing, not to what your position is called.
Jersey numbers carry the force of law
This is the part that surprises people. In most sports a squad number is administrative. In American football it is a rule.
A player wearing 50 to 79 is ineligible to catch a forward pass. Not by convention — by rule, regardless of where they line up.
There is a release valve. A player may report to the referee that they are lining up in an eligible position on that play, and the referee announces it to the stadium. That is the mechanism behind the tackle-eligible play: a lineman declares, lines up at the end of the line, and legally becomes a receiver for one snap.
The declaration is public precisely because the number is doing the work of a label. The defence is entitled to know that the number it has been trained to ignore is, this once, allowed to catch the ball.
The numbering rules changed in 2021
The rigid numbering scheme dated from 1973 and stood for almost fifty years. In 2021, on a proposal from the Kansas City Chiefs, the owners loosened it substantially — enough that every skill position became able to wear single digits.
The permitted ranges after that change:
| Position group | Numbers |
|---|---|
| Quarterback | 1–19 |
| Running back, wide receiver, tight end | 1–49, 80–89 |
| Offensive line | 50–79 |
| Defensive line | 50–79, 90–99 |
| Linebacker | 1–59, 90–99 |
| Cornerback, safety | 1–49 |
| Kicker, punter | 1–19 |
Notice what did not move. 50–79 remains the offensive line’s range, because that band is not a stylistic convention — it is the marker of ineligibility, and the eligibility rule depends on it. The league relaxed everything around the constraint while leaving the constraint itself untouched.
This is characteristic of how the sport legislates. Changing an NFL rule needs 24 of 32 owners, and the changes that pass tend to be the ones that loosen presentation without disturbing the mechanics underneath.
Why the sport works this way
Football is the most heavily substituted team sport in the world. Entire units leave the field between plays, and a roster is built as a collection of specialists rather than a set of interchangeable players.
Legislating by position name would be unworkable: a team could rename a role and argue its way around any rule written that way. Legislating by alignment and number is enforceable on the field, in real time, by officials who can see where players are standing and what they are wearing.
So the rulebook regulates the two things visible at the snap, and leaves the taxonomy to coaches. The 22 positions above are real and useful. They are simply not what the rules are written about.
For how scoring works once the ball is caught, see how many points a touchdown is worth. More rules coverage is in rules and techniques.
Frequently asked questions
How many positions are there in American football?
Twenty-two by convention — eleven on offence and eleven on defence, plus specialists on special teams. But most of those names appear nowhere in the rulebook.
Does the NFL rulebook define a quarterback?
No. It regulates where players line up and which of them may catch a forward pass. 'Quarterback', 'running back' and 'wide receiver' are coaching conventions, not legal categories.
How many players must be on the line of scrimmage?
Seven of the eleven offensive players. The remaining four are backs, lined up at least a yard behind the line.
Who is an eligible receiver?
The two players at the ends of the offensive line, and every player in the backfield — up to six eligible receivers in total. Interior linemen are not eligible.
Why can't offensive linemen catch passes?
Two reasons at once: they line up in the interior of the line rather than at an end, and they wear numbers 50 to 79, which makes them ineligible. A player can report to the referee to change that for a play.
Is the quarterback an eligible receiver?
Not when taking the snap from directly under centre. Lined up in the backfield — in shotgun, for instance — the quarterback is a back like any other and is eligible.