Line of Scrimmage Rules?

[Robert Goodman]

In all major codes, team A's line of scrimmage is the vertical plane parallel to the end lines and passing thru the point of the ball as RFP closest to team A's end line. In all American codes, team B's LOS is likewise for their point of the ball; in Canadian football it's 1 yard behind there. The neutral zone is the space between those planes.

However, a player can be "on" his team's line of scrimmage without literally touching that plane. In all major American codes now to be "on" it for team A, you need to have some part of your head (or helmet) beyond the vertical plane parallel to the end lines and passing through the waist of the snapper, and to face approximately forward (i.e. perpendicularly toward the opponent's end line) as judged by the shoulders. (Notice that the snapper merely by touching the ball and facing forward will have his head past the plane of his own waist.) The various codes have little differences regarding the add'l requirement of whether you can lock legs or in some way overlap with other players on the line. The codes also have slight differences regarding team B players being on their LOS.