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, and throughout any overtime period.
At the one-minute mark of any given half or overtime, the referee announces: "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, and so on.) There is one notable exception: the offense, if in the lead, must advance the ball past the line of scrimmage to keep the clock running; on a loss of yardage, the clock is stopped as soon as the ball is blown dead and remains stopped until snapped again. This keeps the offense moving and the ball in play, avoiding "sandbagging" via the quarterback kneel, a tactic common in the NCAA and NFL to run out the clock with minimum risk. It also rewards defensive play, as a tackle for loss automatically stops the clock.
In the former X-League, after the one-minute warning or in 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.