It's a game I learned at school. I only know 1 version of it and it is called elimination. You keep throwing a tennis ball against a wall. If someone catches the ball before it hits the wall the person who threw it has to run and touch the wall before the person who caught it hits the wall with the ball. You must throw the ball. You can't pick the ball up and touch the wall even if you are close to it. If someone catches the ball after it hits the wall and it doesn't bounce, the person who throw it is out. You make up boundries and if it goes out of bounds the person who threw it yells butter, someone runs and gets the ball and the rest have to run and touch the wall before the person who has the ball throws and hits the wall. If you throw the ball and it hits the ground before the wall or if it doesn't hit the wall that person is out. If the ball slips out of the persons hands they must run and touch the wall before someone picks it up and throws it against the wall.