Squash is governed by the rules of the World Squash Federation (WSF), used at all levels including the professional circuit run by the Professional Squash Association (PSA). Below are the most common rule violations in singles and doubles, how each is defined, and how to avoid them.
Obstruction and Interference (Let vs. Stroke Situations)
Interference is one of the most common violations. After completing a reasonable follow-through, a player must make every effort to clear so that, when the ball rebounds from the front wall, the opponent has:
- a fair view of the ball;
- unobstructed access to reach it;
- space for a reasonable swing;
- the freedom to hit the ball to any part of the front wall.
Failing to provide all of these is interference, such as blocking the path to the ball, impeding the swing, or obscuring the view. Play stops and the referee (or the players, if self-officiating) decides between a let or a stroke:
- Let: the rally is replayed with no penalty, used when the striker could have made a good return and the opponent was making every effort to avoid the interference.
- Stroke: the point is awarded to the obstructed player, used when the failure to clear prevented a good return, or the striker would have made a winning return.
- No let: given when there was no interference, it was so minimal it did not affect play, or the striker could not have made a good return anyway.
A 2024-2025 doubles rule adds that an opponent must not deliberately block the server or server's partner from moving around the court after the serve; doing so can be a stroke for deliberate interference. Deliberate or dangerous interference (body-checking, persistent crowding) can also draw conduct penalties.
How to avoid obstruction:
- Recover to a free space after each shot, making every effort to clear.
- Avoid stopping in the direct line between your opponent and the ball.
- If you risk hitting your opponent with the racket or ball, hold your shot and ask for a let ("Let, please") rather than swinging.
- Never use your position to block deliberately.
- In doubles, call "yours" or "mine" to avoid collisions.
Foot Faults on Serve
At the moment the server strikes the ball, one foot must be in contact with the floor inside the service box, with no part of that foot touching any boundary line. A foot on or inside the box is fine; a toe or heel even slightly on the line is a foot fault. The penalty is a fault, and in modern softball squash that ends the rally and gives the opponent the point. There is no second serve.
Officiating is tightening: the PSA, with World Squash Officiating, has directed referees to call foot faults when they see them, since stepping on the line can confer a fractionally more forward position. These are line calls, not typically reviewable by video.
How to avoid foot faults:
- Know the service box lines, and check your feet when practising serves.
- Stand a few inches further back than you think necessary, so a slight slide stays off the line.
- Use a visual cue, such as tape just inside the box in practice.
- Set your feet before the service motion rather than stepping during the strike.
Players switching from tennis should note there is no second serve, so the rule is unforgiving.
Serving Errors and Faults
Even with correct feet, a serve is good only if all of the following are true:
- Correct contact: drop or throw the ball and strike it on the first attempt before it bounces more than once.
- Front wall between the lines: the ball must hit the front wall first, between the service line and the out line. Too low (the tin or below the service line) is down; touching or above the out line is out.
- Lands in the opposite back quarter: after the front wall, unless volleyed, the ball must bounce first in the back quarter opposite the server's box, past the short line, without touching a boundary line (lines are out).
Any serve that hits the front wall in the wrong spot, fails to reach the back quarter, or touches a line is a fault and the opponent wins the rally. In doubles the mechanics are the same on a larger court, with each team having two servers in turn.
How to avoid serving faults:
- Aim high enough above the service line for a safety margin; a high lob serve is easier to get in than a low hard one.
- Practise depth so the ball bounces deep in the opposite corner, closer to the back wall; a floor marker helps.
- Use the side wall in singles for a tricky rebound, but ensure it first lands in the correct quarter; in doubles, aim at the receiver's body rather than risk an out serve.
- Develop a routine: check your stance, focus on the front-wall target, and swing smoothly rather than rushing.
Improper Return of Serve
Not being ready: the rules allow a let if the receiver is not ready and does not attempt to return. If unprepared, raise your hand to signal rather than swinging; if you swing at all, you are deemed ready and lose the point if you miss. Even when a let is allowed for the receiver not being ready, if that serve was itself a fault, the server loses the rally. Servers should check the opponent appears ready before serving.
Volleying the serve: the receiver may volley a serve, a strong attacking move, but a serve flying out or short may have been a fault, so volleying it gives away a free point. If a serve looks like it is going out or not landing in the quarter, let it go; once you strike it you cannot claim a let or fault.
Doubles, correct receiver: at the start of each game a team designates one player to receive in the right box and one in the left, fixed for the game. Only the designated player may return a serve to that side; if the partner poaches it, the rally goes to the serving side.
How to avoid return mistakes: in singles, use the brief pause before the serve to get into position, watch the server, and signal if you need a moment. In doubles, agree who takes left and right before the match (you can change between games, not during), stay in your own box until the serve is struck, and trust your partner rather than poaching.
Double Bounces ("Not Up")
You may let the ball bounce only once on the floor before returning it. A return that bounces more than once before being struck is not up and ends the rally. Referees use three calls:
- "Not up": the ball was not struck correctly, bounced more than once, or touched the striker or their clothing.
- "Down": the ball hit the tin or the floor before reaching the front wall.
- "Out": the ball went out of court.
In friendly play, etiquette strongly encourages calling your own double bounces and downs; if players disagree, casual games can replay a let, while refereed matches rely on the official or video review. The rule is the same in doubles, where either partner can take the shot, so clear communication keeps one of you reaching the ball in time.
How to avoid double bounces:
- Read the ball early off the opponent's racket to gain retrieval time.
- Return to a ready position near the T after each shot so you are not scrambling.
- Build speed and footwork; an extra half-second from a quick first step often saves the rally.
- Take the ball early on the volley where possible to remove the risk entirely.
- In doubles, call shots early ("Mine") so neither player hesitates.
Player Interference and Safety Considerations
Hitting an opponent with the ball
If your shot hits your opponent before reaching the front wall, the rally stops. It is usually a stroke to you when the ball was going directly to the front wall on your first attempt and you had not turned; if it would have hit another wall first it is usually a let, unless it would have been a winning return (a stroke). Never aim at your opponent, and if a safe path was available but you chose a risky one, you may be penalized for dangerous play. If there is a risk of injury, hold your shot and ask for a let. Protective eyewear is mandatory in sanctioned doubles play.
Hitting your opponent or partner with the racket
This usually happens on the backswing or follow-through, and it is the striker's responsibility to swing without endangering anyone. If an opponent is too close, do not swing, ask for a let. Many doubles teams agree that the back player takes balls behind the front player, so the front player is not hit from behind.
Deliberate movement to cause interference
Drifting into your opponent's path or sticking out an elbow after your shot is not allowed and can bring a stroke against you or a conduct warning. A player must make every effort to avoid interference and not make unnecessary contact: play the ball, then get out of the way.
Calling lets and arguing
Asking for lets without genuine cause, or arguing calls, is frowned upon; repeated baseless requests may be denied as no let, and dissent can earn conduct warnings. Only stop play when you have a valid reason, such as being blocked or fearing a collision, and accept the referee's decision.
Staying safe and fair
You share a tight space, so always know where the other player is and request a let before a crash rather than risking contact. In doubles, watch your partner as well as the opposition, and use a basic understanding such as the front player taking short balls and the back player the deep ones until you switch.
Conclusion
Knowing these common violations keeps you from giving away free points:
- obstruction (lets and strokes);
- foot faults;
- serving faults;
- return-of-serve errors;
- double bounces;
- general interference.
All of these come from the official WSF rules and professional standards. Internalize them until they are second nature, keep a copy of the WSF rules handy or ask a coach or referee when in doubt, and you will play a safer, fairer, and smoother game.
