What passing and handoff plays are legal?

Passing

• One forward pass per play, released from behind the line of scrimmage, and it must cross the line of scrimmage (unless a defender touches it).
• Shovel passes are legal if thrown forward from behind the line and caught beyond it.
• Unlimited backward passes behind the line.
• No intentional grounding: the quarterback can throw the ball anywhere across the line to avoid a sack.
• 7-second pass clock: if the ball isn't thrown in 7 seconds, the play is dead, the down counts and the ball returns to the line of scrimmage (not a safety, even if the QB is in the end zone).
• Every player is an eligible receiver, including the QB after a handoff, pitch or lateral.

Running

• The quarterback can't run directly across the line.
• Handoffs, pitches and laterals are legal behind the line only; once the ball carrier crosses it, only that player may have the ball.
• No center sneak: the QB can't hand, pitch or lateral first to the center.
• Any player receiving a handoff or backward pass can throw from behind the line.
• After a handoff, pitch or lateral, the pass clock ends and all defenders may rush.
• No running plays in the no-run zones (5 yards before midfield and the goal line).