Two people stand at either side of the road, one holding a tennis ball. A point is scored by bouncing the ball off the opposing curb so that it returns to you. If you succeed, you take another shot.
If the ball bounces of the opponent's kerb then starts rolling, you must wait until the ball rolls off the camber to come to one of the players.
This gives the game its only moment of tension; when a car is coming, and with both players shouting at a tennis ball to come to them, it looks to the driver like a heartbreaking tug-of-love between the seperated parents of a tennis ball.