Roshambo

Rock–paper–scissors

A chart showing how the three game elements interact
Genre(s)	Hand game, Ken game
Players	2
Setup time	None
Playing time	Instant
Random chance	High
Skill(s) required	Luck, psychology

Rock-paper-scissors (also known as paper, rock, scissors or paper, scissors, stone) is a hand game usually played between two people, in which each player simultaneously forms one of three shapes with an outstretched hand. These shapes are "rock" (a simple fist), "paper" (a flat hand), and "scissors" (a fist with the index and middle fingers extended, forming a V). A zero-sum game, it has only two possible outcomes other than a tie: one of the two players wins, and the other player loses.

A player who decides to play rock will beat another player who has chosen scissors ("rock crushes" — or sometimes "blunts" — scissors"), but will lose to one who has played paper ("paper covers rock"); a play of paper will lose to a play of scissors ("scissors cut paper"). If both players choose the same shape, the game is tied and is usually immediately replayed to break the tie. Originating from China and Japan, other names for the game in the English-speaking world include roshambo and other orderings of the three items, with "rock" sometimes being called "stone".

Rock-paper-scissors is often used as a choosing 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 non-random behavior in opponents.

The players usually count aloud to 3, or speak the name of the game (e.g. "Rock! Paper! Scissors!" or "Ro Sham Bo!"), each time either raising one hand in a fist and swinging it down on the count or holding it behind. They then "throw" by extending it towards their opponent. Variations include a version where players use only three counts before throwing their gesture (thus throwing on the count of "Scissors!" or "Bo!"), or a version where they shake their hands three times before "throwing".

The first known mention of the game was in the book Wuzazu () by the Chinese Ming-dynasty writer Xie Zhaozhi () (fl. ca. 1600), who wrote that the game dated back to the time of the Chinese Han dynasty (206 BC – 220 AD). In the book, the game was called shoushiling. Li Rihua's book Note of Liuyanzhai also mentions this game, calling it shoushiling (t. 手勢令; s. 手势令), huozhitou (t. 豁指頭; s. 豁指头), or huoquan (豁拳).