- Failing to hit the ball into another square
- Allowing the ball to bounce more than once in their own square
- Hitting the ball out of bounds or onto an inside line
- Hitting the ball incorrectly, such as holding, catching or carrying
- Hitting the ball with a part of the body that are not hands
If the ball is touched by another object which is not one of the four players or the floor, this is called interference. The round is started again. Players waiting in line may not touch the ball when in play.
- www.squarefour.orgrules –visit this website for more information.