Rock paper scissors originated in China during the Han Dynasty (206 BC – 220 AD), where it was known as "shǒushìlìng" (手势令), literally "hand gesture commands." The book Wuzazu by Xie Zhaozhi, written during the Ming Dynasty (around 1600), mentions that this game already existed in the Han era and was used to settle bets at banquets. The three original signs were the frog, the snake, and the slug — a cycle in which the frog eats the slug, the slug dissolves the snake, and the snake devours the frog.
The game spread to Japan during the Edo period (1603–1868) under the name "sansukumi-ken" (三竦みけん), a term designating any game with three gestures forming a cycle. The most popular variant, "jan-ken" (じゃんけん), adopted the signs we know today: rock (gū), scissors (choki), and paper (pā). Jan-ken became a fundamental element of Japanese culture, used not only as a children's game but also to settle everyday decisions. The cry "jan-ken-pon!" accompanying the throw is still recognized worldwide today.
The game arrived in Europe in the late 19th century, introduced through trade with Japan after the Meiji era (1868). The first written mention in English dates to 1924, in an article in The Times of London describing the rules under the name "zhot." In France, the game became popular in schoolyards after World War II, with the rhyme "pierre-papier-ciseaux, un-deux-trois!" North America adopted it under the name "Roshambo" — a term whose etymology remains debated, with some attributing it to the Count de Rochambeau, a hero of the American War of Independence.
Far from being a purely random game, rock paper scissors has been the subject of serious scientific study. In 2014, a team from Zhejiang University led by Zhijian Wang analyzed 360 games played by 72 participants and discovered a recurring behavioral pattern: winning players tend to repeat their gesture, while losers switch following the cyclical order rock → paper → scissors. This unconscious strategy, dubbed "win-stay, lose-shift," contradicts the notion of a purely random game and opens the door to exploitation strategies.
In game theory, rock paper scissors is a classic example of a zero-sum game with no Nash equilibrium in pure strategies. The only Nash equilibrium is the mixed strategy: playing each sign with a probability of 1/3. John Nash himself, Nobel laureate in economics in 1994, used this type of game to illustrate his work. Artificial intelligence researchers have also seized upon it: in 2011, a team from the University of Tokyo created a robot capable of winning 100% of the time by using a high-speed camera that detects the shape of the opponent's hand in 1 millisecond — before the human gesture is fully formed.
Rock paper scissors became spectacularly institutionalized in the 21st century. The World RPS Society, founded in Toronto in 2002, organized annual world championships with prizes of up to $50,000. In 2005, Florida federal judge Gregory Presnell ordered the lawyers of both parties in a case to settle a procedural dispute by a game of rock paper scissors, ruling that both sides were behaving "like kindergartners." The auction house Christie's used the game in 2005 to decide who would sell an Impressionist collection worth $20 million — Sotheby's president played paper, while Christie's representative, advised by the 11-year-old daughter of one of his clients, chose scissors and won the contract.