A play that ends up out of bounds in the NFL can bring up tricky ramifications for the officiating crew. While the rules concerning out of bounds plays are similar to those in college and high school football, subtle differences exist as well. In addition, NFL rules on being forced out of bounds periodically go through revisions.
Receiving a Pass
Many plays in the NFL are made along the sidelines. For a reception to be made legally, a receiver must catch the ball and come down with both feet clearly in bounds. If the receiver jumps up for a pass and catches it but comes down with one foot inbounds and then the other foot comes down out of bounds, the pass is ruled incomplete. In college and high school football, a receiver only has to get one foot inbounds. If the NFL receiver gets even a toe on the sideline, the pass is still ruled incomplete. Close catches along the sidelines are often challenged by coaches and reviewed by the replay official and the referee in charge of the game.
When a play ends with a ball carrier going out of bounds, the clock stops until the referee sets the ball back at the line of scrimmage and deems that play is ready to begin again. However, if a play ends up out of bounds in the last two minutes of the first half or the last five minutes of the second half, the clock stops and does not restart until the ball is snapped on the next play.
Re-entering the Field of Play
A player may not run out of bounds and then run back inbounds to make a play. For example, a receiver may not run down the sidelines, step out of bounds and make a catch. If a player makes a catch under those circumstances, a penalty flag is thrown for illegal touching. However, if the player is shoved out of bounds by a defensive player and then gets back inbounds as quickly as possible, the illegal touching penalty flag is not thrown, and the catch can be ruled as legal by the officials.