A penalty is a broken rule, and the referee marks it by throwing a small yellow flag onto the field. The team at fault usually loses yards.
What the yellow flag means
The first thing to know is that the flag flying does not stop the action straight away. Play runs on to its natural end, and only then does the referee announce what happened and enforce it.
Enforcement almost always means moving the ball. An offensive foul pushes it backwards, a defensive foul moves it forwards. Some defensive fouls do something stronger than yardage and hand over a fresh set of four attempts, no matter the distance. That is what a commentator means by an automatic first down.
There is one quirk worth knowing early, because it looks like generosity and is really arithmetic. The team that was fouled can decline the penalty. If what happened on the play was better for them than the yards would be, they simply wave it off and take the play.
The penalties you will see most
There are dozens in the book. A handful account for most of what you will actually see, and by ESPN’s count offensive holding and false start each make up more than a tenth of all flags thrown.
| Penalty | Cost |
|---|---|
| Offensive holding | 10 yards |
| False start | 5 yards |
| Defensive holding | 5 yards and an automatic first down |
| Defensive offside | 5 yards |
| Unnecessary roughness | 15 yards |
| Delay of game | 5 yards |
| Offensive pass interference | 10 yards |
| Defensive pass interference | Spot of the foul, and an automatic first down |
Offensive holding is blocking with an illegal grip, grabbing or hooking rather than pushing. False start is an offensive player moving before the snap, which is why a noisy home crowd can be a real weapon: players who cannot hear the count twitch early. Defensive holding is grabbing a receiver who is trying to get away. Unnecessary roughness covers late or dangerous hits and costs the most of the common ones, at fifteen yards.
That last column has one entry that does not look like the others, and it is the one worth understanding properly.
Pass interference: the one with no limit
Every other penalty on that list costs a fixed number of yards. Defensive pass interference costs however far the ball travelled.
Start with what it actually is:
NFL rulebook, Rule 8, Section 5, Article 1 (Definition). It is pass interference by either team when any act by a player more than one yard beyond the line of scrimmage significantly hinders an eligible player’s opportunity to catch the ball… When the ball is in the air, eligible offensive and defensive receivers have the same right to the path of the ball and are subject to the same restrictions.
Two useful things are buried in there. The first is “more than one yard beyond the line of scrimmage”, which is the line between interference and holding: the same grab closer in is holding instead. The second is that both players have equal right to the ball. A defender is allowed to go for it. He is not allowed to stop the receiver going for it.
Then the part that makes it the biggest swing in the game:
NFL rulebook, Rule 8, Section 6 (Enforcement Spot). Pass interference by the defense is enforced from the spot of the foul.
Spot of the foul, with no cap. Commit it fifty yards downfield and the ball goes fifty yards downfield, with a fresh set of downs on top. It is a purely NFL severity: college football caps the same foul at fifteen yards, which is why the argument about it never quite dies.
The no-call that changed the rule
The clearest illustration of that power is a call that was never made.
NFC Championship game, 20 January 2019, Saints against the Rams, level at 20-20 with under two minutes left. Drew Brees threw to Tommylee Lewis. The Rams’ Nickell Robey-Coleman arrived helmet first, well before the ball did, and no flag came. New Orleans had to settle for a field goal instead of running the clock down; the Rams tied it, won in overtime, and went to the Super Bowl. Roger Goodell addressed it ten days later, saying the league’s head of officials had told Sean Payton straight after the game that “that’s a play we want to have called.”
The league’s response was the one experiment aimed at that exact problem: for the 2019 season, pass interference became reviewable, both when it was called and when it was not.
It did not work. Across the 2019 season and playoffs, 102 plays were reviewed and only 24 calls were changed, a reversal rate under a quarter, and officials and coaches never settled on what the replay standard even was. An NFL vice-president later described the experiment as having “failed miserably”. It was gone by 2020, and pass interference has been unreviewable ever since. How the rest of the review system works is in replay and challenges decoded.
So the most powerful single call in the game is also the one nobody can go back and check.
Common questions
What is pass interference in the NFL?
Pass interference is when a player significantly hinders an opponent’s chance to catch a catchable pass, more than one yard beyond the line of scrimmage, while the ball is in the air. Defensive pass interference moves the ball to the spot of the foul with an automatic first down, so there is no limit on how many yards it can cost.
What are the most common NFL penalties?
Offensive holding and false start are the two you will see most, several times a game between them. Defensive holding, offside and pass interference are close behind.
What is holding in American football?
Holding is illegally grabbing or hooking a player who does not have the ball, to block or slow him down. Offensive holding costs 10 yards and is the most common penalty in the sport. Defensive holding costs 5 yards and gives the offense an automatic first down.
Where to go next
- NFL rules decoded: how the whole game fits together
- NFL downs explained: what an automatic first down actually hands over
- Scoring decoded: the other thing that moves a scoreboard
- Replay and challenges decoded: what officials can and cannot look at again
Penalties are Rule 8 and Rule 12 of the official NFL rulebook, published by NFL Football Operations, and the Video Rulebook shows most of them in real game clips.