Rock, rock, rock. Rock beats rock Rock beats rock Rock beats rock Therefore The psychological best play in Rock, Rock, Rock is to pick rock This is because your opponents will expect you to pick rock and therefore pick rock, not expecting you to pick rock instead

They just hot eachother with a rock until one gives up or dies.

They played rock, leaf, stick. Leaf covers rock Rock breaks stick Stick stabs leaf Simpler times.

rock, pointy rock, flexible and flat rock

They played Rock, Papyrus, Spear