This game is played with many people. A person starts the game by throwing a ball against a wall. Anyone playing grabs the ball and yells spud. As soon as the person says spud, everyone freezes where they are. The person with the ball throws it at someone and tries to hit anywhere one that persons body except the head. If the ball hits the person, he or she is out. If the ball hits the head of the person, the person who threw the ball is out. If someone catches the ball before it hits the ground, the person who threw the ball is out. As soon as the ball leaves the throwers hands, everyone can move and try to get the ball and become the thrower.
I learned this game at the Gymnast Factory in Houston, Texas around the age of eight or nine. We would play this game after gymnastics practice if we had any free time before practice was over. The coaches would use it as a reward if we had had a good practice. Many times, coaches would announce at the beginning of practice that if we obtained certain new gymnastics skills during practice, we would be allowed to play Spud at the end. If we did a really good job, the coaches would have more than just the girls gymnastics team to play; they would also get the boys gymnastics team and also the trampoline team.
This game is played by mostly older children because it is too fast paced and dangerous for small children to play. Many times adults will play this game too; coaches would often play Spud with us.
Often times we would gang up on a person and try to get them out. Sometimes we would do this if we did not like the person, but most of the time we would gang up on a member of the opposite sex as a way of flirting.
I am not sure why the game is called Spud. Perhaps the game was first played using a potato instead of a ball. I have not seen this game played anywhere except at the Gymnast Factory, but it is very similar to dodgeball and could be a variant of it.