The latest version of the official WSF Rules of Singles Squash (Nov 2021)
Squash is played in a confined space, often at a high speed. Two principles essential for orderly play are:
Players must always place safety first and not take any action that could endanger the opponent.
Players must respect the rights of the opponent and play with honesty.
9.1 If the ball, on its way to the front wall, hits the non-striker or the non-striker’s racket or clothing, play must stop; then:
9.1.1 if the return would not have been good, the non-striker wins the rally;
9.1.2 if the return was going directly to the front wall, and if the striker was making a first attempt without having turned, a stroke is awarded to the striker;
9.1.3 if the ball had hit or would have hit any other wall before the front wall and the striker had not turned, a let is allowed, unless the return would have been a winning return, in which case a stroke is awarded to the striker;
9.1.4 if the striker had not turned but was making a further attempt, a let is allowed;
9.1.5 if the striker had turned, a stroke is awarded to the non-striker, unless the non-striker made a deliberate movement to intercept the ball, in which case, a stroke is awarded to the striker.
9.2 If the ball, on its return from the front wall, hits a player before bouncing twice on the floor, play must stop; then:
9.2.1 if the ball hits the non-striker or the non-striker’s racket, before the striker has made an attempt to strike the ball and no interference has occurred, the striker wins the rally, unless the striker’s position has caused the non-striker to be hit, in which case a let is allowed;
9.2.2 if the ball hits the non-striker, or the non-striker’s racket, after the striker has made one or more attempts to strike the ball, a let is allowed, providing the striker could have made a good return. Otherwise, the non-striker wins the rally;
9.2.3 if the ball hits the striker and there is no interference, the non-striker wins the rally. If interference has occurred, Rule 8 (Interference) applies.
9.3 If the striker hits the non-striker with the ball, the Referee must consider if the action was dangerous and rule accordingly .