The distinction between a fumble and a muff should be kept in mind in considering rules about fumbles. A fumble is the loss of player possession of the ball. A muff is the touching of a loose ball by a player in an unsuccessful attempt to obtain possession.
A fumble may be advanced by any player on either team regardless of whether recovered before or after ball hits the ground.
A fumble that goes forward and out of bounds will return to the fumbling team at the spot of the fumble unless the ball goes out of bounds in the opponent’s end zone. In this case, it is a touchback.
On a play from scrimmage, if an offensive player fumbles anywhere on the field during fourth down, only the fumbling player is permitted to recover and/or advance the ball. If any player fumbles after the two-minute warning in a half, only the fumbling player is permitted to recover and/or advance the ball. If recovered by any other offensive player, the ball is dead at the spot of the fumble unless it is recovered behind the spot of the fumble. In that case, the ball is dead at the spot of recovery. Any defensive player may recover and/or advance any fumble at any time.
A muffed hand-to-hand snap from center is treated as a fumble.