If an offensive player is outside of the tackle box and squares up to a defender, lowers his head and delivers a forcible blow with the crown of the helmet, the team will be assessed a 15-yard penalty from the spot of the foul, according to the NFL, which released a video with the rules changes for the 2013 season on Monday.
Should the offensive player have a long run before delivering such a blow, the penalty will be assessed from the spot, but it will remain a first-and-10. If the ball-carrier is stopped short of the line of scrimmage, the penalty will be assessed from the end of the play as a dead-ball foul.
If a player is on the edge of the tackle box or in a goal line situation, the play will not be considered a penalty.
The tackle box is designated as the space between the outside shoulders of the left and right tackles, extending to the backline behind the offense and three yards beyond the line of scrimmage in front of the line.
The league announced rules changes in four other scenarios:
*On field-goal and extra-point formations, the defense cannot line up more than six players on the line of scrimmage on either side of the long-snapper. Should they do so, it is a live-ball foul and the five-yard illegal formation penalty will be assessed after the play is complete. However, if the offense shifts from a non-traditional formation for the kick, the rules no longer apply and they can line up over the long-snapper and over-stack the line.
Defensive players are also prevented from delivering low blocks on the guards and tight ends in a kicking formation, and pushing players into the line of scrimmage. Both scenarios will result in 15-yard personal-foul penalties and an automatic first down for the offense.
The long-snapper is now considered a defenseless player and therefore, cannot be hit in the head and/or neck area or be hit with the crown of a defender’s helmet.
*The NFL has outlawed the peel-back block, where a player starts in the tackle box, then leaves, and returns to make a block below the waist of a defender toward their own end line. Doing so will result in a 15-yard penalty.
*There has been a modification to the “tuck rule,” which now states that loss of control once the tuck motion has been initiated is considered a fumble. If the quarterback’s hand is still in a passing motion, the play will be considered an incomplete pass.
*Instant replay will have two changes.
If a coach throws a red flag to challenge a scoring play or turnover, which are automatically reviewed, the play will still be reviewed. However, the challenging team will be charged one of their remaining timeouts or assessed a 15-yard penalty if they are absent of timeouts.
Previously, the play could not be reviewed if coaches challenged plays automatically looked at by the replay official, and his team was assessed a 15-yard penalty regardless of the remaining timeouts.
Also, the defense can challenge whether a player had possession of a catch, but later fumbled down the field.