Rock-Paper-Scissors is a game played by two or more people where the players use their hands to form certain symbolic shapes after a count of three with aim of the game being to form a symbolic shape that beats the other player's symbolic shapes.
Amongst the three most popular symbolic shapes used, the "rock" symbol beats scissors, the "scissors" symbol beats paper and the "paper" symbol beats rock; if both players throw the same shape, the game is tied and the players play again.
The first known mention of the game was in the book Wuzazu by the Chinese Ming Dynasty writer Xie Zhaozhi, who wrote that the game dated back to the time of the Chinese Han Dynasty (206 BC – 220 AD). The game was then imported to Japan and subsequently became popular, various versions of the game were formed, which became known as sansukumi-ken games.
Today, the best-known sansukumi-ken is called "Jan-ken" and is the game that the modern version of Rock-Paper-Scissors derives from.
By the early 20th century, rock-paper-scissors had spread beyond Asia through increased Japanese contact with the west.
- The game is often used as a decision-making method in a way similar to coin flipping, drawing straws, or throwing dice. Unlike truly random selection methods, however, rock-paper-scissors can be played with a degree of skill by recognizing and exploiting behavior in opponents.
- One of the original Japanese versions of the game was known as "Mushi-ken" and used the Frog, Slug and Snake. The "frog" (represented by the thumb) is superseded by the "slug" (represented by the little finger), which, in turn is superseded by the "snake" (represented by the index finger), which is superseded by the "frog".
- The most popular game in Japan was "Kitsune-ken". In the game, a kitsune defeats the village head, the village head defeats the hunter, and the hunter defeats the kitsune. Unlike Mushi-ken or Rock-Paper-Scissors, Kitsune-ken is played by making gestures with both hands.
- In many real-time strategy, first-person shooter, and role-playing video games, it is common for a group of weapons or unit types to interact in a rock-paper-scissors style, where each selection is strong against a particular choice, but weak against another (such as cavalry being strong against archers, archers being strong against pikemen, and pikemen being strong against cavalry). Such game mechanics can make a game somewhat self-balancing, and prevent gameplay from being overwhelmed by a single dominant strategy.