In most cases, the offense has the option of declining this penalty if a defender jumps offside. If a defender is offside when the ball is snapped and the play has not been whistled dead, the offense can choose the result of the play instead of accepting the penalty.
This is advantageous if the offense can produce a big play that is more beneficial than the smaller penalty against the defense.
- The offense can choose to accept an offside penalty or decline it if they prefer the outcome of the play in which the infraction took place.
- If a defender has a clear path to the quarterback, the play will be whistled dead, resulting in a five-yard penalty against the defense and a repeat of the down.
- Many skilled quarterbacks have a specific cadence when calling out signals to manipulate the defense and try to get them to jump offside.
What Constitutes an Offsides and What is the Penalty?
Offsides can be called if any part of a defensive player is in the “neutral zone” when the ball is snapped. In football, the neutral zone is anywhere between the two points of the ball at the line of scrimmage. 
If a defender jumps into the neutral zone but can remove himself from the area before the ball is snapped, no penalty will be called.
However, if the defender makes contact with an offensive player, the play will be whistled dead. This is called encroachment. The play will also be whistled dead if a defender enters the neutral zone and has a clear line to the quarterback. Officials usually refer to this as a defender being “unabated to the quarterback.” In these cases, the referee has made a judgment call that the safety of the quarterback is at risk, and allowing the play to continue could result in an injury. 
This penalty is not always a product of the offense calling out signals or actively jumping offside.
Here we see Dee Ford of the Chiefs lineup in the neutral zone, negating an interception that almost certainly would have won the Chiefs the game and sent them to the Super Bowl. Patriots quarterback Tom Brady didn’t have to do anything but snap the ball as Ford was already committing an infraction.
Regardless of whether the defender is called for being offsides, encroachment, or unabated to the quarterback, the penalty is the same. In each case, the defense loses five yards of field position and the down is repeated.
Why Would You Decline An Offsides Penalty?
There are situations where a defender may jump offsides, but the ball is still allowed to be snapped and the play carried out. In these situations, the offense knows that there’s already been a penalty committed. At this point, the worst outcome for the offense is a five-yard gain and a repeat of the down.
In many cases, the offense will take advantage of the situation to attempt a deep pass in the hopes of picking up a big gain or drawing a pass interference penalty for an even bigger chunk of yardage. 
Smart quarterbacks may attempt a pass that they generally wouldn’t, throwing into a tight window with the knowledge that even if their pass is intercepted the potential turnover will be wiped out thanks to the offsides call.
- WHAT IS PASS INTERFERENCE IN FOOTBALL?
- WHAT IS THE PLAY-ACTION PASS?
- WHAT IS A FORWARD PASS IN FOOTBALL? (DEFINITION & RULES)
Examples of Declined Offsides
Several quarterbacks will use a hard count to try to get a defender to jump offside. This usually entails the quarterback mixing up the snap count or calling out signals with an extra hard cadence that convinces the defender that the ball is about to be snapped. Especially on passing downs, defensive linemen and blitzing linebackers will try to anticipate the snap count, allowing them to get past the offensive line to pressure or sack the quarterback.
Aaron Rodgers of the Green Bay Packers has become especially adept at the hard count, drawing defenders offsides, recognizing the advantage, and taking a shot down the field.
He’s also shown aptitude at surprising the defense by pivoting to a hurry-up offense that catches the defense trying to make substitutions. Rodgers will snap the ball while defenders are still running off the field, resulting in a “too many men on the field” penalty which has the same consequences as being offsides.
While most defensive offsides penalties are accepted, we’ve seen several different scenarios where it’s advantageous for the offense to decline this penalty and take the result of the play. Smart teams recognize these “free plays” when the ball is snapped, and this added awareness can lead to huge chunk plays that can alter the game a lot more than a five-yard penalty and a repeat of the down.
The next time you’re watching an NFL game, keep your eyes on the defensive line at the snap of the ball, and if someone jumps or lines up offsides, take note of how the quarterback reacts, and how the offense’s play style changes in response.