The NFL will implement several rules changes ahead of the 2017 season.

Below are a few of the most important rule changes:

NFL celebration rules relaxed

In May, the NFL announced the return of a few fan favorite celebration rules and some clarification on what is an illegal celebration.

This season and beyond, the NFL will allow players to celebrate on the ground, in groups and by using football as a prop.

Any act that is directed at an opponent, determined to be violent or offensive and any use of an object other than a prop (pylon, goal post, etc.) will still remain a violation.

Prohibiting players from jumping over offensive lineman to block a field goal or extra point

According to the NFL, several players expressed concerns over players jumping over linemen and the line of scrimmage in an attempt to block an extra point attempt. Before the rule change, the player could jump over the line of scrimmage as long as they did not contact another player.

The NFL will no longer allow a player to jump over the line of scrimmage in an attempt to deflect the kick because of the danger to linemen and the player jumping.

A receiver can be a defenseless player

A receiver running a route will receive defenseless player protection when the opposing player defends from the side or behind. Contact with the defender’s crown of the helmet to any part of the receiver’s body is a foul. Hits with the helmet are legal if the defender does not hit the receiver with the crown of the helmet.

If the receiver displays a blocking posture, he is exempt from defenseless player protection.

Low hits against the quarterback

Game officials and referees will continue to enforce rules that protect quarterbacks from low hits. If a defender drives their shoulder, forearm, chest or helmet below the quarterback’s knee area is not allowed. If the contact is unavoidable, for example, if the defender is pushed into the passer, a foul does not result.

Once the quarterback tucks the ball and moves outside the pocket or rushes the ball, he no longer is protected from low hits.

Contact downfield between receivers and defenders

Game officials will play closer attention to contact between receivers and defenders at the end of routes in 2017.