What happens if the ball hits my opponent or me?

Play stops and the referee decides under World Squash Singles Rule 9.

Your shot hits your opponent on its way to the front wall:

• Your return wouldn't have been good: your opponent wins the rally.
• It was going straight to the front wall, you hadn't turned and it was your first attempt: stroke to you.
• It would have hit a side wall first: let, unless it would have been a winner (then stroke to you).
• You hadn't turned but were making a further attempt: let.
• You had turned: stroke to your opponent, unless they deliberately moved to intercept the ball.

The ball, coming back off the front wall, hits a player:

• It hits your opponent before you've attempted a shot, with no interference: you win the rally, unless your position caused them to be hit (then a let).
• It hits your opponent after you've made an attempt: let if you could have made a good return, otherwise your opponent wins the rally.
• It hits you (the striker) with no interference: your opponent wins the rally.

If a player hits the opponent with the ball, the referee also considers whether it was deliberate or dangerous.