Rules of Squash
11.1 If the ball breaks during a rally, a let is allowed for that rally.
11.2 If a player stops play to appeal that the ball is broken, and it is found that the ball is not broken, that player loses the rally.
11.3 If the receiver, before attempting to return serve, appeals that the ball is broken, and the ball is found to be broken, the Referee, if uncertain when it broke, must allow a let for the previous rally.
11.4 A player who wishes to appeal at the end of a game that the ball is broken must do so immediately and before leaving the court.
11.5 The ball must be changed if both players agree or if the Referee agrees with one player’s request.
11.6 If a ball has been replaced, or if the players resume the match after a delay, the players may warm up the ball. Play resumes when both players agree or at the discretion of the Referee, whichever is sooner.
11.7 The ball must remain in the court at all times, unless the Referee permits its removal.
11.8 If the ball becomes wedged in any part of the court, a let is allowed.
11.9 A let may be allowed if the ball touches any article in the court.
11.10 No let is allowed for any unusual bounce.
Full Set of Rules