What is "one-minute warning"

n. (context American football English) In the AFL, a warning given with one minute to go before the end of a half, after which special rules apply, eg, stoppage of the game clock after very first down.

The one-minute warning or the one-minute timing rule is a rule in the Arena Football League and other indoor American football leagues that dictates the flow of the game in the final minute of a half or overtime.

At the one-minute mark of any given half or OT the referee will announce "One Minute Timing Rule in effect". During the final minute of play, the game clock changes from a continuously running clock (except for scores and time-outs) to a clock that mirrors NCAA rules (stopping on first downs, out of bounds, incompletions, etc.) There is one notable exception: the offense, if in the lead, must advance the ball forward, past the line of scrimmage, to keep the clock running; failing to do this, the clock will be stopped as soon as the ball is blown dead and will remain stopped until snapped again. This keeps the offense moving and the ball in play through the end of the game, thereby avoiding "sandbagging" via the quarterback kneel, a tactic common in the NCAA and NFL to run out the clock in the least risky way possible. It also rewards defensive play, as a tackle for loss automatically stops the clock.

In the former X-League, after the one-minute warning near the end of a game or overtime, the "X-Bonus" rule came into play. All scoring during the final minute of play was worth double what it is normally worth, and a special black football was used.