Apparently its like “bad news basketball” which was a game I played as a kid during recess which involved a basketball and basketball goal and from there we just made the rules up as we went. It usually ended with a tackle that led to a pile-on and wrestlilng match for the ball. It was also a great game. But Slamball threw in the genius suprise of trampolines. As if the sport wasnt great enough they allowed goal tending body checking and face offs. Take all the great bits out of every sport, smash  them together and then you have Slamball.