Tug-of-war is a time-honored tradition between dogs and humans. Dogs seem to implicitly understand how the game is played – pull as hard as you can until you have gain possession of the object, or until the human dislocates his or her amr.
The dog pictured here seems to have some problem grasping how it works though. He appears to be more interested in getting an extended belly rub than taking possession of the rope.
Courtesy of imgur.com