Rock-paper-scissors

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 or Scissor-Paper-Rock, is a zero-sum 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 together forming a V). The game has only three possible outcomes other than a tie: a player who decides to play rock will beat another player who has chosen scissors ("rock crushes 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. Other names for the game in the English-speaking world include roshambo and other orderings of the three items, sometimes with "rock" being called "stone".

The game 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 () (traditional Chinese: 五雜組; simplified Chinese: 五杂组) by the Chinese Ming-dynasty writer Xie Zhaozhi () (traditional Chinese: 謝肇淛; simplified Chinese: 谢肇淛; 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 (traditional Chinese: 手勢令; simplified Chinese: 手势令; literally: "hand command"). Li Rihua's (traditional Chinese: 李日華; simplified Chinese: 李日华) book Note of Liuyanzhai (traditional Chinese: 六硯齋筆記; simplified Chinese: 六砚斋笔记) also mentions this game, calling it shoushiling (traditional Chinese: 手勢令; simplified Chinese: 手势令; literally: "hand command"), huozhitou (Chinese: 豁指头), or huoquan (Chinese: 豁拳).