Not every call can be reviewed, and that surprises people. A coach can ask officials to look again at some rulings by throwing a red flag, but only clear, factual ones: was the pass caught, was the player down, did the ball cross the line. Judgement calls like holding and pass interference are off-limits, however wrong they look. Here is where the line sits, and why.
How a challenge works
A head coach carries a red flag through the game. To challenge a call, he throws it onto the field before the next play begins, and officials stop to review the ruling on a video monitor. If the replay shows clear evidence the call was wrong, they overturn it. If it is too close to be sure, the ruling on the field stands.
There is a cost, which is what keeps coaches honest. Each coach gets two challenges a game, and earns a third only if he wins at least one of the first two. A challenge needs a timeout in hand, and if the review does not go his way, he loses that timeout. So a coach who challenges a hunch and loses has handed away something he may badly need late in the game. In 2024, Pittsburgh’s Mike Tomlin threw the flag on a play that could not be challenged at all, and the Steelers simply lost a timeout for it.
Two things happen without any flag. Scoring plays and turnovers are reviewed automatically every time. And inside the last two minutes of each half, and all of overtime, coaches cannot challenge at all: the replay booth in the stadium and the league’s command centre in New York take over and decide what gets a second look.
What can and cannot be reviewed
The whole system runs on one idea: objective, not judgement. A camera can settle a factual question. Did the foot land in bounds? Did the knee touch before the ball came loose? Did the ball break the goal line? Those can be reviewed. So can whether a pass was caught, whether a runner was down, and the spot of the ball.
What cannot be reviewed is a judgement call, and that includes almost every penalty: holding, offside, unnecessary roughness, false start, and pass interference. Even a blown call that everyone in the stadium can see is not open to challenge. The league tried the other way once. After a notorious missed pass-interference call, it made that penalty reviewable for a single season in 2019, decided the experiment had failed, and dropped it again. You can read that whole story on the NFL penalties and pass interference page. The short version: subjective calls stay off the table.
The line is shifting a little. Since 2025, the replay booth can help fix some clear-cut penalty situations, such as too many players on the field, or whether a ball was tipped before an interference call. But those are the objective edges of penalties. The core judgement, was that holding, was that interference, still belongs to the officials in real time.
The catch that changed the rule
The clearest example of replay deciding a game is a play Dallas fans call “Dez Caught It”.
On 11 January 2015, the Cowboys were at Lambeau Field in the playoffs, trailing the Green Bay Packers and facing fourth down with under five minutes left. Tony Romo threw deep to Dez Bryant, who caught the ball, took two steps and reached for the goal line as it touched the ground. It was ruled a catch on the field. Packers coach Mike McCarthy challenged, and on review the referee overturned it to incomplete, because under the catch rule at the time Bryant had not held the ball all the way through hitting the ground. Dallas turned the ball over on downs, Green Bay ran out the clock, and the Packers won 26-21.
Cowboys coach Jason Garrett disagreed flatly: “Dez made a great catch on the ball.” He was not alone, and that is the point. The call followed the rule, and the rule was so confusing that the NFL rewrote it a few years later. It is replay at its most powerful and its most maddening at once: a factual review, applied correctly, that still felt wrong to almost everyone watching.
Common questions
How does a coach’s challenge work?
A head coach throws a red flag before the next play to ask officials to review a call on video. Each coach gets two challenges, and a third if he wins at least one. He needs a timeout to challenge, and loses one if the review does not go his way. Inside the last two minutes of a half, the replay booth handles reviews instead.
Can you challenge a penalty in the NFL?
Mostly no. Judgement calls like holding and pass interference cannot be challenged, however obvious the mistake looks. Replay is limited to clearer questions, such as whether a pass was caught, a player was down, or the ball crossed a line. Since 2025, some objective fouls, like having too many players on the field, can be fixed by the replay booth.
Where to go next
- NFL Rules Decoded: how the whole game works.
- Penalties & Pass Interference Decoded: the judgement calls replay will not touch, and the no-call that proved why.
- Scoring Decoded: including what counts as a touchdown, the call replay reviews most.
Want it straight from the source? Instant replay is Rule 15 in the NFL’s official rulebook, and the league’s Video Rulebook shows real reviews with clips.