False Start vs Neutral Zone Infraction: NFL Pre-Snap Fouls

The NFL rulebook keeps four fouls on the same few inches of turf, all in Rule 7, Section 4, all worth five yards. A false start is an offensive player moving early in a way that looks like the snap. Offside is any player with part of his body in or beyond the neutral zone at the instant the ball is snapped. Encroachment is a defender who crosses and touches an opponent or the ball before the snap. A neutral zone infraction is a defender whose jump makes a nearby blocker flinch, or who gets a clear run at the quarterback. The first, third and fourth kill the play with a whistle. Offside alone lets it run.

That last difference decided the AFC Championship Game on January 20, 2019. About a minute remained when a deflected Tom Brady pass dropped into the arms of Kansas City cornerback Charvarius Ward. The Chiefs led 28-24 at Arrowhead Stadium and the interception would have all but sent them to the Super Bowl. It never counted. Edge rusher Dee Ford had lined up with his helmet past the football, and referee Clete Blakeman announced defensive offside. Because the foul let the play run, Brady got to throw the pass at all; because it was a foul, New England kept possession, scored, and won 37-31 in overtime.

False start vs offside vs encroachment: four flags sorted by three questions

Officials do not pick among these fouls by feel. They ask who moved, whether anybody was touched or made to react, and whether the ball had been snapped. Every combination of answers has one name.

Foul	Who commits it	What happened	Whistle	NFL rule
False start	Offense	A set player moved in a way that simulated the start of the play	Immediate	7-4-2
Encroachment	Defense	A defender entered the neutral zone and touched an offensive player or the ball before the snap	Immediate	7-4-3
Neutral zone infraction	Defense	A defender's move drew a flinch from a nearby blocker, or left him unblocked on the quarterback's side of the line	Immediate	7-4-4
Offside	Either team	A player was in or beyond the neutral zone when the ball was snapped	Flag only; the play runs	7-4-5

Three things in that table surprise people who have watched football for decades.

Encroachment and offside are not two words for one mistake. The college and high school books use the terms differently, which is where the confusion starts, but in the NFL encroachment requires contact and offside requires a snap. A defender who jumps across, touches nobody, scares nobody and scrambles back in time has committed neither.

The neutral zone infraction does much of the work. A defender who jumps and draws a flinch would otherwise produce an argument about who went first. The rulebook settles the argument in advance by charging the man who started it.

And offside is the only one of the four that the offense can commit as well as the defense. That half of the rule cost Kansas City a touchdown in 2023, and it gets its own section below.

• 5Yards for each of the four fouls
• 3Fouls that stop the play at once
• 1Fouls that let the play run
• 10Seconds run off for a late false start

Standard enforcement under NFL Rule 7, Section 4 and Rule 4, Section 7. The runoff applies only to an offensive dead-ball foul with the game clock running after the two-minute warning.

The neutral zone: the length of the football, from sideline to sideline

Everything here is measured against a strip of ground that most broadcasts never draw. Rule 3, Section 18 defines the neutral zone as the space between the forward and backward points of the ball, extended to both sidelines. The ball lies with its long axis pointing at the goal lines, and the rulebook's specification for that axis is 11 to 11¼ inches. So the neutral zone is a band a little under a foot deep and as wide as the field.

It does not exist all the time. The zone is established when the ball is made or declared ready for play, and from that moment the restrictions of Rule 7, Section 4 switch on. A defensive tackle who is standing over the ball jawing at the center while the officials are still spotting it has broken no line, because there is no line yet.

Who may be in it

One man. The snapper has to reach into the zone to grip the ball, and the definitions allow for it: no part of his body may be beyond the neutral zone, which is a different thing from being in it. His hands are on the ball. His helmet usually hangs over it.

Every other offensive lineman is held to a stricter standard. No part of his body may be in the neutral zone at the snap. He must also be close enough to count as being on the line, which the book measures by whether his helmet breaks a vertical plane through the snapper's beltline. Tackles live in the gap between those two requirements, as far back as the beltline permits and no farther, because depth buys them a head start against a speed rusher. The roles along the front are laid out in our guide to the offensive line positions.

The defense has no beltline rule. A defender may crowd the ball as tightly as he likes provided nothing of his, not a fingertip and not the crown of a helmet, is in or beyond the zone when the ball moves.

The false start rule: a set player who simulates the snap

The article is worth reading whole, because its key verb is not "move." It is a false start if, after the ball is ready and before the snap, an offensive player who has assumed a set position moves in such a way as to simulate the start of a play. Any quick, abrupt movement by one player, or by several in unison, that simulates the start of the snap qualifies.

Simulation is the test. A guard who slowly turns his head to hear the call has moved and not simulated anything. A tackle whose shoulders jerk upward has. So has a tight end who rocks his weight onto his front hand, and a running back who lurches forward out of his stance.

The rulebook then lists cases where it takes the judgment away from the officials.

• Interior linemen. A center, guard or tackle who takes or simulates a three-point stance and then changes position or moves the hand that is on the ground has committed a false start. No abruptness is required. A lineman still in a two-point stance may reset into a three-point one if he comes to a complete stop before the snap.
• Receivers on the line. Once the offense has been set for a full second, an eligible receiver on the line who moves forward is guilty whether the movement is quick or slow.
• The man taking a shotgun snap. He may shift his feet. A quick, abrupt movement is a foul, and the book gives its own example: thrusting his hands forward when no snap comes with it.
• A player in motion. A sudden movement toward the line by the motion man is a false start, not a motion foul, a distinction covered in our guide to the illegal shift and illegal motion rules.

Why the whistle comes at once

The official is told to blow the whistle immediately, "whether the snap is made or there is a reaction by the defense." There is no play, no result to choose from and nothing for the defense to decline in any practical sense.

The reasoning is partly fairness and partly safety. A flinch by the offense is an invitation to the defense to come across, and a defender who accepts it has done what the offense's own movement told him to do. Let the play run and the offense would be rewarded for the fake. Stop it and nobody gets hit by a rusher charging a quarterback who thinks the play is dead.

One practical consequence follows. When a lineman flinches and the defender across from him then barrels into the backfield, the defender is not offside and has not encroached. The false start came first and the ball was dead before he crossed.

The offside rule: in or beyond the neutral zone when the ball is snapped

Article 5 is the shortest of the group. A player is offside when any part of his body is in or beyond the neutral zone, or beyond a restraining line for an onside kick, when the ball is put in play.

"When the ball is put in play" carries the whole distinction. Until the center moves the football, a defender who has drifted into the zone has done nothing that this article punishes. If he gets back before the snap, having touched nobody and frightened nobody, there is no foul of any kind. The rule says so directly in the article next door: no immediate reaction, a return to a legal position, no contact, no foul.

That is why offside is a live-ball foul and the others are not. The violation is only complete at the snap. By then the play has begun, and a play that has begun is allowed to finish.

Two ways to be offside

A defender is caught by this rule in one of two ways, and they look nothing alike.

The first is lining up there. Ford did not jump. He put his hand down with his head across the front tip of the ball and stayed put until the snap, a mistake of alignment, the same on the fiftieth viewing as the first. Edge players do it more than interior linemen because they are trying to shave the distance to the tackle's outside shoulder.

The second is the mistimed jump. A rusher guesses at the snap count, starts a beat early and is across the ball when it moves. If the center snaps it right then, the flag is offside. If the center does not, the defender is in trouble of a different kind, because now he is past the line with the offense still set, and whichever of the three dead-ball calls fits will be made.

What the flag is worth

Five yards from the previous spot, with the down replayed. There is no automatic first down attached to defensive offside. On third-and-4 the five yards are enough to move the chains by themselves; on third-and-8 the offense gets third-and-3.

None of the four fouls on this page can be challenged by a coach. Alignment at the snap is not on the list of reviewable rulings in Rule 15, and anything not on that list stays as called, a limit explained in our guide to the NFL's challenge and replay rules. Kansas City could do nothing about the Ford call except watch it.

The free play: what the offense gains and what a quarterback risks

A quarterback who sees a yellow flag fly from the sideline as he takes the snap knows something the defense would prefer he did not. The down is, at worst, going to be replayed five yards closer to the goal line. Whatever happens next is optional.

So he throws deep. Receivers are coached to convert their routes the moment a defender jumps, and the usual conversion is a straight sprint up the field. If the pass is caught, the offense declines the penalty and keeps the gain. If it is incomplete, the offense takes the five yards. If it is intercepted, the offense takes the five yards and the interception is erased from the game, as Ward's was.

1. 1The snapA defender is in or beyond the neutral zone when the ball moves. The flag is thrown and no whistle follows.
2. 2The play runsThe quarterback, knowing the down cannot end badly, usually throws deep to a receiver who has converted his route.
3. 3Good resultA long completion or a touchdown stands. The offense declines the penalty.
4. 4Bad resultAn incompletion, a sack, an interception or a fumble is wiped out. The offense accepts five yards and replays the down.
5. 5Offense also foulsHolding or offensive pass interference offsets the offside. The down is replayed from the original spot with no yardage.

The sequence follows the enforcement rules for a live-ball defensive foul in the NFL rulebook. The offense makes the choice in every case unless it also fouled.

Aaron Rodgers built a reputation in Green Bay on exactly this. His method had two parts. A varied cadence got the defender to move. Then a center who had been drilled to snap the ball the instant he saw a helmet cross turned a dead-ball flinch into a live-ball foul before the defender could retreat.

Where the free play goes wrong

It is less free than the name suggests, and the costs are specific.

The first is the whistle. If the defender who jumped has a clear path to the quarterback, or a lineman flinched in response, the play is dead as a neutral zone infraction and the deep ball is thrown into a stopped game. The quarterback does not always know which flag he has been given.

The second is the flag that was never thrown. Quarterbacks have seen a defender jump, assumed the call and lobbed a pass into coverage, only to learn that the officials judged the man to have been back in time. That interception counts.

The third is the offense's own foul. A tackle who grabs the rusher who beat him by jumping early turns five free yards into nothing, because the holding offsets. And if the offense commits a 15-yard foul on the play, the rulebook's five-versus-15 rule discards the minor foul and enforces the major one. The free play becomes a 15-yard loss.

Encroachment: a defender who touches an opponent or the ball

On February 1, 2015, in Glendale, Arizona, Malcolm Butler intercepted Russell Wilson at the goal line and New England had the ball and a 28-24 lead with 20 seconds left in Super Bowl XLIX. It also had a problem. The Patriots were backed up against their own goal line, and a kneel-down from there risked a safety that would have handed Seattle two points and the ball.

Brady went to the line and used his voice. Seattle defensive end Michael Bennett came across before the snap and made contact, the whistle blew, and the call was encroachment. Five yards. With room behind him, Brady could kneel, and the game was over.

The article that covered it is two sentences long. It is encroachment if a defensive player enters the neutral zone and contacts an offensive player or the ball prior to the snap, or if he interferes with the ball during the snap. Officials are to blow their whistles immediately.

Contact is the entire foul. The defender need not hit anyone hard; a hand brushing the guard's shoulder pad is enough. The definition in Rule 3 puts it in the present tense: a player is encroaching when any part of his body is in the neutral zone and he contacts an offensive player or the ball before the snap.

The ball counts as an opponent

The second clause protects the snap itself. A nose tackle lined up over the center is inches from the football. If he swipes at it before the snap or gets a hand on it as the center starts his motion, that is encroachment even though he never touched a man. Without this clause, the cheapest way to wreck an offense would be to slap the ball out of the center's hands on every down and accept five yards whenever it went wrong.

Why there is no free play

Because the down never starts. Encroachment is enforced from the line of scrimmage before the snap, and the offense gets five yards and the same down. It cannot decline in favor of anything, since nothing happened. A defense that is going to cross the line early is better off, from its own point of view, touching somebody: an encroachment costs five yards and an offside can cost a 40-yard completion.

The neutral zone infraction: the jump that makes a blocker flinch

Take a defensive end who anticipates the count and lunges into the neutral zone. The left tackle across from him, seeing a man coming at his chest, lifts his hand and rocks back. Whistles. Two players have moved before the snap, one on each side.

Without a rule for it, the easy call would be a false start on the tackle, since his is the movement the officials can be sure of. Article 4 of Rule 7, Section 4 gives the opposite answer. The defender caused it, so the defender pays. The rulebook describes the lineman as reacting immediately to protect himself against impending contact, which is a fair account of what a 310-pound man does when another one launches at him.

The article has three parts.

The unimpeded path. A defender moves beyond the neutral zone before the snap and is parallel to or beyond an offensive lineman, with an unimpeded path to the quarterback or kicker. No contact is needed and no flinch is needed. This is the call referees announce as "unabated to the quarterback."

The flinch. A defender enters the neutral zone before the snap and causes an offensive player in close proximity to react. If nobody reacts and the defender gets back without touching anyone, there is no foul.

The late line. During the last two minutes of a half, the ball is snapped before all members of the defense are on their side of the line of scrimmage, with the offense legally set. A defense that is slow getting back after a play cannot use its own disorder to turn a hurry-up snap into a harmless offside.

Why "unabated" is a dead-ball call

The first clause exists for the quarterback. A rusher who is past the blockers before the snap is going to arrive at full speed against a passer who has not finished his drop and may not have seen him. An ordinary offside lets the play run because the blockers are still between the rusher and the ball. Remove the blockers and the rulebook removes the play.

Officials have to decide in a fraction of a second whether a defender who jumped is offside with a blocker still in his way, in which case the flag is thrown and the play continues, or unabated, in which case it is whistled dead. Quarterbacks have thrown touchdown passes on what they took for a free play and seen them wiped out because the whistle had already gone. It is the least satisfying outcome on this page, and it is the rule working as intended.

When both sides move: who caused it and who is close enough to react

The flinch clause would be unworkable if any offensive player anywhere could react to any defender. A split end 20 yards from a jumping nose tackle has not been threatened by him. So the rulebook draws a map.

Where the defender entered the neutral zone	Offensive players treated as in close proximity
Directly over the center	The center, both guards, both tackles and a quarterback under center
In a gap between two linemen	The two offensive players on either side of that gap, plus a quarterback under center where that applies
Anywhere else along the front	Offensive players within two-and-one-half positions of the defender
On one side of the ball	A flexed or split receiver lined up on that same side

Inside the map, a reaction is the defense's foul. Outside it, the reaction is a false start in its own right. If a defensive end jumps on the offense's left and the right guard comes out of his stance, the right guard has no claim to have been protecting himself. Five yards against the offense.

The quarterback matters only when he is under center. The rulebook's term is a T-formation quarterback, and it includes him among the players who may react. A quarterback in the shotgun stands several yards deep and has no impending contact to flinch from.

How the crew sorts it out

1. 1Who moved firstIf an offensive player simulated the snap before any defender entered the neutral zone, it is a false start and the defender's reaction is excused.
2. 2Was anyone touchedA defender who entered the zone and contacted an offensive player or the ball has encroached.
3. 3Is he unblockedA defender beyond the zone and level with or past a lineman, with a clear path to the quarterback or kicker, has committed a neutral zone infraction.
4. 4Did a nearby blocker reactA flinch by a player in close proximity is a neutral zone infraction on the defense. A flinch by a player outside it is a false start.
5. 5Was the ball snappedIf none of the above happened and the defender was still in or beyond the zone at the snap, he is offside and the play runs.

The order of questions follows NFL Rule 7, Section 4, Articles 2 through 5. The first four outcomes are dead-ball fouls and the last is a live-ball foul.

The first question is the hard one. A lineman's flinch and a defender's jump can be a tenth of a second apart, and the two wing officials are looking down the line from opposite sides with different players blocking their view. They get together when they disagree. The conference that follows a pre-snap whistle is nearly always about sequence: which helmet moved first.

The hard count: what a quarterback may do with his voice

The rules on drawing a defender across are not symmetrical between sound and movement. A quarterback may shout anything he likes in any rhythm he likes. He may bark the snap word and not have the ball snapped. He may go silent for three seconds and then start again. Nothing in Rule 7 regulates his voice.

His body is another matter. Item 5 of the false start article reads: any obvious attempt by the quarterback or other player in position to receive the snap to draw an opponent offside is a false start. In practice that means a head that jerks forward with the cadence, hands that shoot out as if to take a snap that is not coming, or a sudden dip of the shoulders. The safe way to run a hard count is to keep the body still and let inflection do the work.

So the line runs between what a defender hears and what he sees. A defensive tackle is expected to watch the ball and move when it moves. A quarterback who deceives his ears has beaten him fairly. One who puts a false picture in front of his eyes has simulated the snap, and that is the offense's foul. How cadences are built, and why a hard count works best at home, is the subject of our guide to what a hard count is and how quarterbacks use it.

The defense has a matching restriction

A defender cannot play the same trick in reverse. Under Rule 4, Section 6, a defensive player aligned in a stationary position within a yard of the line who makes quick, abrupt actions that are not part of normal defensive movement, in an obvious attempt to cause a false start, is guilty of delay of game. The whistle is immediate and the penalty is five yards. A defender walking up to time the snap who pulls up short when the ball does not come is specifically exempted.

Shouting is covered separately and more severely. Defensive acts or words designed to disconcert the offense at the snap, such as calling out a fake cadence, are unsportsmanlike conduct. The rest of what that section treats as stalling is set out in our guide to the NFL delay of game penalty.

Offside by the offense, and the restraining lines on kicks

December 10, 2023, Arrowhead Stadium, Buffalo leading 20-17 late in the fourth quarter. Patrick Mahomes threw to Travis Kelce, who ran, drew the defense and flung a lateral across the field to Kadarius Toney. Toney scored. The flag had been down since the snap, and referee Carl Cheffers announced offensive offside on Toney, who had lined up past the front tip of the ball. The touchdown came off and Buffalo won by the same three points.

Offensive offside is rare enough that the announcement startled people, but the rule has always been there. An offensive player on the line, other than the snapper, may not have any part of his body in the neutral zone at the snap. The snapper may not be beyond it. A wide receiver who sets his front foot past the front tip of the ball is offside in exactly the sense Ford was.

Receivers usually avoid it through a habit. The man on the end of the line looks to the nearest wing official and points at his foot, and the official signals whether he is on the line or off it. That exchange is a courtesy. Kansas City's complaint after the game was that no warning had been given. Cheffers' answer to the pool reporter was that no warning is required, least of all when a player is lined up so far offside that he blocks the officials' view of the ball.

The foul is a live-ball one, five yards from the previous spot. It sits close to the formation fouls in the same part of the book, and the difference is direction. A receiver too far forward is offside; one too far back leaves the offense short of men on the line, which is the problem explained in our guide to what makes an NFL formation illegal.

Kickoffs and onside kicks

A free kick has no neutral zone. It has restraining lines, and offside there means being beyond your line when the ball is kicked.

On the standard kickoff the NFL has used since 2024, the ten coverage players line up with a front foot on the receiving team's 40-yard line and may not move until the ball touches the ground or a player in the landing zone or the end zone. The rulebook splits the possible mistakes. A player beyond the restraining line when the ball is kicked is offside. A coverage man who leaves his spot before he is permitted to has put his team in an illegal formation. Each is five yards. Why the league rebuilt the play that way is covered in our explainer on the NFL's kickoff rule changes.

On an onside kick, which must be declared to the referee in advance, the kicking team lines up on its own restraining line, normally its 35-yard line, and every player other than the kicker and holder must be behind the ball when it is kicked. A man who crosses early is offside in the old sense, and when the kicking team has recovered the ball, the five yards come with a re-kick it did not want. The recovery rules are in our guide to how NFL onside kicks work.

Five yards, but not equal: dead ball, live ball, the runoff and half the distance

The yardage is identical. What comes with it is not.

Foul	Ball status	Marked off from	Clock consequence
False start	Dead	Line of scrimmage, before the snap	10-second runoff if the clock was running after the two-minute warning
Encroachment	Dead	Line of scrimmage, before the snap	None against the offense
Neutral zone infraction	Dead	Line of scrimmage, before the snap	None against the offense
Defensive offside	Live	Previous spot	None
Offensive offside	Live	Previous spot	None

The ten-second runoff

A false start stops the clock. For a team trailing late with no timeouts, a stopped clock is worth more than five yards, and without a further rule every desperate offense would flinch on purpose.

Rule 4, Section 7 closes that door. After the two-minute warning of either half, an offensive foul that stops a running clock during a dead-ball period costs ten seconds as well as the yardage, and the play clock is reset to 30. If fewer than ten seconds remain, the half is over. The offense may keep its ten seconds by spending a timeout. The defense may decline the runoff, which it will do when it is the team that needs the time. Why that stoppage marks the point where the timing rules tighten is covered in our guide to the two-minute warning.

There is never a runoff against the defense. A defender who encroaches late in a half does not cost his team ten seconds, though the same section stops a defense from using a deliberate jump to freeze the clock for its own benefit: the offense chooses whether the clock restarts on the referee's signal or on the snap.

Half the distance

No distance penalty may move the ball more than half the way from the enforcement spot to the offender's goal line. An offense that false starts at its own 6-yard line goes back to the 3, not the 1. A defense that jumps at its own 4-yard line gives up two yards. Inside the 1, a defensive offside moves the ball half of whatever is left, and then half of that.

The NFC Championship Game on January 26, 2025, showed where that arithmetic ends. Washington linebacker Frankie Luvu twice hurdled the line early trying to beat Philadelphia's quarterback sneak at the goal line, the ball moved inches each time, and after one more Washington jump referee Shawn Hochuli announced that the team had been advised a score could be awarded if it happened again. The authority comes from Rule 12, which lets the referee award the score after a warning when a defense commits repeated fouls to prevent one.

What college and high school football call the same movements

A fan who learned the terms on Friday nights or Saturdays is using a different dictionary from the one NFL referees announce from, and has good reason to be confused.

Movement	NFL	College (NCAA)	High school (NFHS)
Set offensive player simulates the snap	False start, dead ball	False start, dead ball	False start, dead ball
Defender crosses and touches an opponent	Encroachment, dead ball	Offside, dead ball	Encroachment, dead ball
Defender crosses and a blocker flinches	Neutral zone infraction, dead ball	Offside, dead ball	Encroachment, dead ball
Defender in the zone at the snap, no contact	Offside, live ball	Offside, live ball	Encroachment, dead ball; the snap is not allowed
Offensive player in the zone	Offside, live ball	Encroachment by the offense	Encroachment, dead ball

The college book

The NCAA rulebook has no neutral zone infraction by that name. It files every defensive version under offside and separates them by whether the ball stays dead: a defender who makes contact, who threatens a lineman into reacting or who is charging past the line toward a back is stopped by the whistle, and one who is merely across at the snap produces a live-ball flag and a free play, much as in the NFL. College officials reserve "encroachment" for the offense, for a player other than the snapper who is in or beyond the neutral zone once the snapper has touched the ball. The yardage is five in every case. Other places where the two books part company are collected in our guide to college football and NFL rule differences.

The high school book

Under the National Federation rules used by most state associations, one word covers nearly everything. Once the ball is ready and the snapper has his hands on it, any other player who breaks the plane of the neutral zone has encroached. The foul is complete at that instant. The defender cannot get back, the ball is not snapped and there is no such thing as a free play.

It is the simplest of the three systems and the hardest on defenders, and it was written with teenage linemen in mind: the rule removes the collision before it happens. It also means a player moving up to the college game has to learn that getting back counts, and one who reaches the NFL has to learn four names for what he once knew as one.

The professional version asks the most of its officials. It makes them judge contact, sequence, proximity and a clear path in the half-second before a snap, and then decide whether to let 22 men play on. That is a great deal of judgment for five yards. It is also the only one of the three books that lets a quarterback turn a defender's mistake into 40 yards, and no team that has benefited from a free play has argued for the simpler rule. More of the site's coverage of the sport is collected on our American football page.