A match is the best of three games. Each game is to nine points, unless the score reaches eight-all. At eight-all the receiver (non-server) has to choose to play either to nine points (known as "Set One") or to ten points (known as "Set Two"). (There is no requirement that a player needs to be two points ahead to win a game).

Only the server scores points. When the server wins a rally he or she scores a point; when the receiver wins a rally he or she becomes the server.

Play commences with a service. The player to serve first is decided by the spin of a racket. Thereafter, the server continues serving until losing a rally, when the opponent becomes the server and the server becomes "hand out".

The player who wins the preceding game serves first in the next game.

At the beginning of each game and when the service changes from one player to the other, the server can serve from either service box. After winning a rally the server then continues serving from the alternate box.

To serve a player stands with at least part of one foot on the floor within the service box. For a service to be good, it is served directly onto the front wall above the service line and below the out line so that on its return, unless volleyed, it reaches the floor within the back quarter of the court opposite to the server's box.

A return is good if the ball, before it has bounced twice on the floor, is returned correctly by the striker onto the front wall above the tin and below the out line, without first touching the floor. The ball may hit the side walls and/or the back wall before reaching the front wall.

A return is not good if it is "NOT UP" (ball struck after bouncing more than once on the floor, or not struck correctly, or a double hit); "DOWN" (the ball after being struck, hits the floor before the front wall or hits the tin) or "OUT" (the ball hits a wall on or above the out line).

After a good service has been delivered the players hit the ball in turn until one fails to make a good return.

A rally consists of a service and a number of good returns. A player wins a rally if the opponent fails to make a good service or return of the ball or if, before the player has attempted to hit the ball, it touches the opponent (including racket or clothing) when the opponent is the non-striker.

NOTE: AT ANY TIME DURING A RALLY A PLAYER SHOULD NOT STRIKE THE BALL IF THERE IS A DANGER OF HITTING THE OPPONENT WITH THE BALL OR RACKET. IN SUCH CASES PLAY STOPS AND THE RALLY IS EITHER PLAYED AGAIN ("A LET") OR THE OPPONENT IS PENALISED.

If a player strikes the ball, which, before reaching the front wall, hits the opponent, or the opponent’s racket or clothing, play stops.

If the return would have been good and the ball would have struck the front wall without first touching any other wall, the striker wins the rally, provided the striker did not "turn".

If the ball either had struck, or would have struck, any other wall and the return would have been good, a let is played.

If the return would not have been good, the striker loses the rally.

If the striker has either followed the ball round, or allowed it to pass around him or her - in either case striking the ball to the right of the body after the ball had passed to the left (or vice-versa) - then the striker has "TURNED" (see below).

If the ball strikes the opponent after the striker has turned, the rally is awarded to the opponent.

If the striker, while turning, stops play for fear of striking the opponent, then a let is played. This is the recommended course of action in situations where a player wants to turn but is unsure of the opponent’s position.

A player, after attempting to strike the ball and missing, may make a further attempt to return the ball.

If a further attempt would have resulted in a good return, but the ball hits the opponent, a let is played.

If the return would not have been good, the striker loses the rally.

When it is his or her turn to play the ball, a player is entitled to freedom from interference by the opponent.

To avoid interference, the opponent must try to provide the player with unobstructed direct access to the ball, a fair view of the ball, space to complete a swing at the ball and freedom to play the ball directly to any part of the front wall.

A player, finding the opponent interfering with the play, can accept the interference and play on, or stop play. It is preferable to stop play if there is a possibility of colliding with the opponent, or of hitting him or her with racket or ball.

When play has stopped as a result of interference the general guidelines are:

The player is entitled to a let if he or she could have returned the ball and the opponent has made every effort to avoid the interference.

The player is not entitled to a let (i.e. loses the rally) if he or she could not have returned the ball, or accepts the interference and plays on, or the interference was so minimal that the playerís access to and strike at the ball was not affected.

The player is entitled to a stroke (i.e. wins the rally) if the opponent did not make every effort to avoid the interference, or if the player would have hit a winning return, or if the player would have struck the opponent with the ball going directly to the front wall.

A let is an undecided rally. The rally does not count and the server serves again from the same box.

In addition to lets allowed as indicated in the paragraphs above, lets can be allowed in other circumstances. For example, a let may be allowed if the ball in play touches any article lying on the floor, or if the striker refrains from hitting the ball owing to a reasonable fear of injuring the opponent.

A let must be allowed if the receiver is not ready and does not attempt to return the service, or if the ball breaks during play.

Play is expected to be continuous in each game once a player has started serving. There should be no delay between the end of one rally and the start of the next one.

In between all games an interval of 90 seconds is permitted.

Players are permitted to change items of clothing or equipment if necessary.

If an injury occurs which involves bleeding, the bleeding must be stopped before the player can continue. A player is allowed a reasonable time to attend to a bleeding wound.

If the bleeding was caused solely by the opponent’s action, the injured player wins the match.

For an injury not involving bleeding, it must be decided whether the injury was either caused by the opponent or self inflicted or contributed to by both players.

If caused by the opponent, the injured player wins the match if any recovery time is needed.

If self-inflicted, the injured player is allowed 3 minutes to recover and must then play on, or concede a game using the 90 second rest period between games to recover.

If contributed by both players, the injured player is allowed an hour to recover.

Offensive, disruptive or intimidating behavior in squash is not acceptable.

Included in this category are: audible and visible obscenities, verbal and physical abuse, dissent, abuse of racket, court or ball, unnecessary physical contact, excessive racket swing, unfair warm-up, time-wasting, late back on court, deliberate or dangerous play or action and coaching (except between games).