Official Rules of Racquetball

6.1 - Basic Return Rule

In general, the ball remains in play as long as it is bouncing. However, the player may swing only once at the ball and the ball is considered dead at the point it stops bouncing and begins to roll. Also, anytime the ball rebounds off the back wall, it must be struck before it crosses the short line on the way to the front wall, except as explained in Rule 6.2.