A legal snap depends on the ball, the motion and the receiver. A messy exchange can still leave a live ball.

A recovery behind the line can be advanced. A recovery beyond it ends the play, with touching deciding possession.

A motionless football can remain live. Officials wait briefly when nobody attempts to recover an abandoned ball.

A normal kickoff that first lands before the receiving 20 is dead immediately. A later bounce cannot fix it.

A score can make the ball dead before the whistle. Runners, receivers and kicks satisfy different scoring conditions.

Contact with an inbounds official usually leaves the ball live. The official’s location and the ball’s status still matter.

A loose ball striking overhead equipment is dead, and the down is replayed. The NFL restores the clock to the snap.

Eligible end players can release early. Most other players must stay within one yard of the line until the kick.

A punt, place kick or drop kick must satisfy the line of scrimmage rule. A second kick has an additional restriction.

The recovery spot is not always the enforcement spot. Start with where possession was lost and when the foul occurred.

A forward handoff has different rules from a forward pass. Location, receiver eligibility and possession changes determine legality.

Most passing play fouls start from the previous spot, but interference, grounding and certain major fouls have specific exceptions.

Returning inbounds does not automatically restore a receiver’s right to touch the pass first. The reason for the exit matters.

A receiver can interfere by pushing off or illegally blocking downfield. Ordinary route traffic is not automatically a foul.

The answer depends on receiver alignment, location and the passing threat. Other low block restrictions still apply.

Defensive pass interference is usually a spot foul. Timing, location, catchability and meaningful restriction decide the call.

A fair catch signal can end the receiving team’s return opportunity even when another teammate catches the kick.

Illegal touching by an originally ineligible receiver costs five yards. Unlike another illegal touching rule, it does not include loss of down.

Receiver eligibility depends on alignment and numbering, with special rules for reporting, leaving the field and tipped passes.