In gridiron football, intentional grounding is a violation of the rules where "a passer...throws a forward pass without a realistic chance of completion." This typically happens when a quarterback about to be sacked passes the ball toward an area of the field with no eligible receiver. Were it not for this rule, the quarterback could easily turn the sack into an incomplete pass which, by rule, would advance the ball back to the line of scrimmage.
A ball carrier, in any location, commits intentional grounding when throwing a pass that does not reach the line of scrimmage; for instance, throwing the football down near himself. An exception is that the quarterback is allowed to spike the ball immediately after receiving it from the center. At the cost of a down, this is a way to stop the clock that a team may use when it has no time outs left.
Intentional grounding is also called if all of the following components are present:
Imminent pressure. If the passer does not face "imminent loss of yardage," then there is no penalty. It is not a violation when the passer is not about to be tackled but simply misses his receiver because the receiver fails to run the route the quarterback expects.
Location. The quarterback must be inside the "tackle box," the area between the two offensive tackles on the line. If the quarterback scrambles to either side and is closer to the sideline than that side's tackle lined up, there is no penalty. This loosening of the rule was passed in 1993 in order to protect quarterbacks
Target of the pass. The ball must be passed where there is no eligible receiver, such as well out of bounds. If a receiver is nearby but fails to catch the ball, or if a defender deflects the pass, there is no penalty.
After a flag is thrown, the officials may confer to decide whether all these components were present, and may "pick up the flag" upon finding there was no intentional grounding.
The penalty for intentional grounding has several components so that the offense gains no benefit from the violation:
The offense is backed up 10 yards from the line of scrimmage or to the spot of the pass, whichever is most disadvantageous.
The offense loses the down rather than replaying it - for most other penalties the offense is permitted to replay the down if the defense accepts the penalty.
If the quarterback threw the pass from his team's own end zone, inside or out of the tackle box, the penalty results in a safety being scored by the defense.
The offense cannot commit a penalty as a form of clock management, because offensive penalties with less than one minute left in the half include a ten-second runoff on the game clock.
In the NFL Pro Bowl, intentional grounding is legal in order to make the game safer.
