Squash (sport)
If one player gets in the way of the other who is trying to get to the ball, that player can ask the referee for a "let," which results in the point being replayed.  If a player prevents the other player from swinging at the ball, creating a dangerous situation, that player can appeal for a "stroke," which results in the player who could not safely hit the ball winning the point.  If the referee feels that the swinging player could not have reached the ball, or did not make every effort to get to it, then the referee can award "no let," which means that the point ends as it would have had no one asked for a let or stroke.