When Hammurabi wished to bring levity to the situation, He would stand on a person’s right, and reach over and tap on that person’s left shoulder. As a result, the victim would invariably look to his left, where no one was standing, all would laugh, or by law, Hammurabi would stone them.
The Oldest Trick in the Book also covers such classics as Socrates’ "Ahomosezwut" and Schmelling’s defeat of Himmler with the "Who can Hit the Softest?" trick.