The boundary lines in football are the lines on the field that separates the field of play from the out of bounds areas. The areas considered out of bounds are the sidelines and the area behind the end line, which is behind either end zone. The boundaries are marked off by boundary lines, white lines similar to the yard lines on the field.
You can think of anything inside of the rectangle in the picture above as inbounds. Everything on or outside of this rectangle is out of bounds.
A player is inbounds so long as they stay within the boundary lines, either sideline and either end line. The inbounds area is made up of the field of play and two end zones at either end of the field of play.
Football Out of Bounds
A player is out of bounds if they are not in the field of play or end zone. If a player is involved in a play and they go out of bounds, they cannot re-enter the field of play until the next play or if they are carrying the football, the play is called dead.
Football Boundaries Rules
The rules of the football boundaries work like this:
- A player must be inbounds to touch the football
- If a player runs out of bounds with the ball, the scrimmage down is over
- A score will not count if a player catches the ball out of bounds
- A player who steps out of bounds without the ball may not re-enter a play, barring certain circumstances
- Players not involved in a play on the sideline may not enter the field of play after play begins
Touching The Boundaries
Football Complete Pass
In college football (NCAA football) and high school football, the catching rule states that a player must have at least one foot inbounds when catching a pass. In the NFL, a player must have both feet inbounds when catching a pass for. Otherwise, the pass is ruled incomplete.
PRO TIP: One foot must be inbounds in high school and college football (NCAA football). Two feet must be inbounds in the NFL.