Wallball is played on a court and with a ‘wall’. The ‘wall’ is actually more like a slanted roof on legs. The court is marked by lines on the ground in front of the wall. If the ball is thrown against the roof and lands outside the court lines it is out.
Each player takes turns to throw the ball against the wall and catch it. Once the ball is caught the player must stop moving. They may leap to throw the ball but the ball must be released before they touch the floor again. The ball can either be hurled at the wall so it bounces off or tossed up and allowed to roll down. If rolling it must come off the end of the court end of the wall not the side of the wall.
The game itself developed in the early days of Edgebury, before Havok became the cities slum there was a poor quarter of Edgebury where the houses were all attached. The children used to throw balls up onto the houses of the roofs and catch it when it tumbled back down.