I am just learning the rules of the game. They were created by the dog where I am house sitting. He has this white plastic strange looking ball that he drops near me and then he hides. He watches me from his hiding places to see if I am going to get the ball or not. He is very patient and quiet. When I finally see it, I throw it to out in the yard and he chases after it. Then he puts it near me again and waits for me to see it and throw it. If I am in the pool while this is happening, of course I can't reach it when he puts it five feet from the side of the pool. So then he will put it closer and closer until I can reach it. He will hide in strange places too. This is a very subtle game. It has taken me several days to finally realize what he has been doing. He is a patient and smart dog.