Racketball has this evil little blue ball that is hard like a rock. If you ever get hit in the eye by one you will never forget it!
When we played (notice I used the past tense because of afore mentioned reason) we hit it against a wall in this cube, tennis has a person on either side of the net. I thought it was fun until the "accident". DH is VERY competative and has been known to lie about rules and cheat so I am not sure what the "real" rules to this game are. I only know that that darn ball is vicious!