What movement causes a flag for "false start" and what doesn't?

Question

I always thought that any movement by the offensive line once they are in a three point stance would draw a flag. Sometimes even the tiniest twitch will cause a flag. But other times I see linemen turning their heads around, or getting up and pointing, or doing all kinds of other not-so-subtle movements and there is no penalty. So what kind of movement is allowed?

Matthew - that is a good explanation. But as for when the quaterback is "set", how would that apply when he is in the shotgun formation?

Answer 1

The offensive line is allowed to move until the quarterback gets set. This would usually be when the quarterback sticks his hands under the center to recieve the snap. Once set only certain types of motion in the backfield are allowed. False Start is any movement by a lineman after the offense is set before the snap. Also any movement by a running back or wide reciever is also a false start after they have set. The center may not rock the ball back and forth or tip the ball up unless he is starting to snap the ball. The quarterback may be called for false start for bobbing his head or simulating a snap. Usually, as in any sport, it is up to the officials to decide what is and is not false start.

Answer 2

all i see a false start happen is when someone will act like they're gonna go just to trick the other teams player and make him go.personally i think thats wrong but its football.and there is alot of wrong stuff that happens but isnt called for hoped this helped you out