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Rock paper scissors

Rock paper scissors is a two-player hand game in which each participant simultaneously chooses one of three gestures representing rock (a closed fist), paper (an open palm), or scissors (two extended fingers forming a V-shape).^[1] The core rules dictate that rock crushes and defeats scissors, scissors cut and defeat paper, and paper covers and defeats rock, with identical choices resulting in a tie that typically prompts a rematch.^[1] Often employed as a simple, impartial method for decision-making in casual settings, the game is played worldwide and serves as an accessible introduction to concepts in game theory, where no single strategy guarantees victory due to the cyclic dominance structure.^[2] The game's origins trace back to ancient China, where an early variant known as shoushiling involved similar hand gestures; it later evolved in Japan by the 17th century as janken or sansukumi-ken, incorporating elements like the insect-themed mushi-ken with frog, slug, and snake gestures, before spreading to Europe and the United States in the early 20th century through immigration and media references, such as a 1921 Washington Herald article.^[1]^[3] In the West, it was initially called "roshambo" or "roshambeau," possibly inspired by unrelated historical figures like the French general Comte de Rochambeau, though no direct connection exists.^[3] Today, rock paper scissors transcends recreation, influencing fields like psychology and artificial intelligence; for instance, a 2012 University of Tokyo robot achieved perfect win rates by predicting human patterns in milliseconds.^[1] Professional competitions, organized by groups like the World Rock Paper Scissors Association, draw international participants with substantial prizes, underscoring its evolution into a competitive sport.^[1] The game also appears in legal contexts for resolving disputes, such as a 2006 U.S. federal court case where a judge ordered attorneys to settle a discovery dispute via rock-paper-scissors.^[4]

Names and Etymology

Etymology

The English term "rock paper scissors" is a direct translation of the Japanese names for the three hand gestures in the game janken: gū (rock, a closed fist), pā (paper, an open palm), and choki (scissors, two extended fingers). This nomenclature entered English through cultural exchanges with Japan in the late 19th and early 20th centuries, as janken evolved from earlier Japanese hand games during the Edo and Meiji periods.^[5] In the West, an alternative name "roshambo" or "rochambeau" emerged in the early 20th century, particularly among Japanese immigrants in the United States; the first documented use of "roshambo" appears in a 1921 Washington Herald article describing the game in Seattle. The term is likely a phonetic rendering of "jan-ken-po," the Japanese chant, with folk etymology sometimes linking it to the French general Comte de Rochambeau, though no direct historical connection exists.^[3] The conceptual roots of these terms trace back to ancient Chinese hand-gesture games, notably shoushiling (手勢令, "hand-gesture command"), which influenced the development of similar games across East Asia via trade routes and cultural diffusion from the Han dynasty (206 BCE–220 CE) onward. A key early reference appears in the Ming dynasty text Wuzazu (c. 1615) by Xie Zhaozhe, who described variants like shoushiling as established pastimes involving symbolic gestures that resolved disputes.^[5]^[6] The first documented English usages of "rock paper scissors" emerged in American publications during the 1920s and 1930s, reflecting the game's growing popularity among children in the West; for instance, it was described in recreational guides like Compton’s Pictured Encyclopedia (1933) as a Japanese import.^[5]^[3] Etymologically, the name connects to a longstanding folklore tradition of hand-sign games in East Asia, where gestures symbolized natural elements or creatures in cyclic dominance, as seen in Japanese sansukumi-ken ("three-way deadlock fist") variants that predated janken and emphasized balanced, ritualistic play.^[5]

Cultural names

In Japan, the game is known as janken, a term derived from the onomatopoeic sounds of hand claps produced during play, specifically mimicking the rhythmic "jan-ken-pon" chant that accompanies the gestures.^[7] This name reflects the game's deep integration into Japanese culture, where it is commonly used for quick decision-making in daily life and media.^[8] In China, the standard Mandarin name is shítou jiǎndāo bù, translating to "rock-scissors-cloth," with players chanting the phrase while forming the hand signs; a variant cǎijiǎn bù emphasizes "guess-scissors-cloth" in some regional contexts.^[9] The game, often called jiǎndāo bù for brevity, is a staple in children's play and social interactions across the country.^[10] Korea refers to the game as gawi bawi bo, meaning "scissors rock cloth," where gawi represents scissors, bawi denotes rock or stone, and bo stands for cloth or paper; it is frequently used in games, shows, and even formal settings like team selections.^[11] Among European languages, the French name is pierre-feuille-ciseaux ("stone-leaf-scissors"), though in Belgium it is often pierre-papier-ciseaux ("stone-paper-scissors"), with feuille or papier both signifying paper in the cyclic rules.^[12] In Spanish-speaking regions, it is called piedra papel o tijera ("stone paper or scissors"), a direct translation chanted in sequence to determine outcomes in play or disputes.^[13] In Indonesia, the game goes by batu gunting kertas ("rock scissors paper"), a literal adaptation of the standard gestures. A distinct variant known as suten or suit (also suwit) uses elephant (raised thumb), human (extended index finger), and ant (pinched fingers) gestures instead, maintaining the cyclic dominance but with different symbols; it is popular in informal settings, particularly among youth.^[14] Across African cultures, the game appears in various hand-game forms with local names, such as mwamba karatasi mkasi in Swahili-speaking East Africa ("rock paper scissors"), used by teachers and children for fair choices, while in South Africa it is sometimes known as ching chong cha, a colloquial term blending phonetic play with the gestures—but widely considered offensive and racist due to its mocking imitation of Chinese language sounds.^[14]

Gameplay

Basic rules

Rock paper scissors is a hand game typically played between two participants, requiring no equipment beyond the players' hands. Each player selects one of three gestures—rock, represented by a closed fist; paper, shown as an open flat hand with fingers extended and together; or scissors, formed by extending the index and middle fingers in a V shape—while concealing their choice initially.^[15]^[16] In a standard single round, players face each other and synchronize their movements by chanting a countdown, such as "Rock, paper, scissors, shoot!" or "One, two, three, shoot!", counting in rhythm. On the final word ("shoot"), both players simultaneously reveal their chosen gesture by extending their hand outward, ensuring neither gains an advantage through anticipation.^[16]^[15] If both players reveal identical gestures, the round results in a tie, and the players replay the round until a decisive outcome occurs. The game can be extended to multiple rounds, often structured as best-of-three or best-of-five, but each round follows this independent procedure. For groups larger than two, the game is adaptable through modifications like relay formats where team members play sequentially.^[16]^[17]

Winning conditions

In the standard game of rock paper scissors, the winning conditions follow a fixed cycle of dominance among the three gestures. Rock defeats scissors by crushing it, scissors defeats paper by cutting it, and paper defeats rock by covering or wrapping it. These rules establish a clear outcome for each possible matchup between different gestures, with identical gestures resulting in a tie.^[18] This structure forms a non-transitive hierarchy, meaning there is no overall superior gesture; instead, each one beats exactly one other and loses to the remaining one, creating a cyclical pattern where rock beats scissors, scissors beats paper, and paper beats rock. This non-transitivity ensures that no single strategy dominates all others, promoting balance in the game's design.^[19]^[20] In multi-round formats commonly used in tournaments, matches are typically decided on a best-of-three basis, where the first player to win two rounds claims victory, though longer series such as best-of-five or best-of-seven may be employed for higher-stakes competitions to reduce the influence of chance.^[18] The game's fairness stems from the equal probability of each gesture prevailing in random play, with each having a one-third chance of winning against an opponent's random choice, assuming no strategic bias. This symmetry underpins the game's use as a neutral decision-making tool.^[21]

History

Origins

The game known today as rock paper scissors traces its roots to ancient China during the Han Dynasty (206 BCE–220 CE), where it emerged as a hand gesture game called shoushiling (手勢令), or "hand gesture command." This early form involved three gestures representing animals in a cyclic dominance: a thumb for a frog, a pinky for a centipede, and an index finger for a snake, with each defeating one and losing to another (snake eats frog, frog eats centipede, centipede poisons snake). The earliest written references to shoushiling appear in Ming Dynasty texts, including Wuzazu by scholar Xie Zhaozhe in the early 1600s, which attributes the game's popularity to the Han era, and Note of Liuyanzhai by bureaucrat Li Rihua, which describes similar gesture-based pastimes.^[6]^[1]^[5] From China, the game spread to Japan, evolving into variants under the umbrella of sansukumi-ken ("three who fear each other"), a category of hand games featuring cyclic rules. By the 17th century, during the Edo period (1603–1868), an early Japanese iteration called mushi-ken gained traction, using gestures for a slug, frog, and snake in a similar dominance cycle, as illustrated in an 1809 depiction. This form transitioned into the more standardized janken (or jan-ken-pon), incorporating rock, paper, and scissors gestures, which became widespread by the late Edo era among children and adults for quick resolutions.^[1]^[5]^[8] In feudal Asia, particularly during Japan's Edo period, janken and its precursors integrated into everyday social practices, serving as a neutral method for dispute resolution among friends, students, and street vendors to settle minor conflicts or allocate tasks without favoritism. The game also appeared in communal settings fostering fair play and quick decision-making in group activities.^[5]^[8]^[22]

Global spread

Rock paper scissors, originating in ancient Asia as a hand game with cyclic dominance, began its dissemination to the West in the early 20th century through Japanese cultural exchanges and immigration.^[1] In Europe, the game first appeared in British records in 1924, when a letter to The Times described a hand game called "zhot," which readers identified as the Japanese jan-ken.^[1] By 1927, a French children's magazine, La Vie au Patronage, detailed the rules under the name "chi-fou-mi," referring to it as a "jeu japonais" and contributing to its rapid adoption among European youth.^[1] These early mentions reflect the influence of traders, missionaries, and expatriates who encountered the game in Asia and introduced it via print media and personal accounts. The game's entry into America occurred in the 1920s as a popular playground activity among children, evolving from immigrant communities on the West Coast.^[3] By the 1930s, it gained broader visibility in media, including a 1932 New York Times article describing its use in Tokyo and its inclusion in the 1936 Handbook for Recreation Leaders under the name "Rochambeau," which standardized it for American recreational use.^[1] Films of the era, such as those depicting schoolyard antics, further embedded it in popular culture, portraying it as a fair method for settling disputes. Post-World War II globalization accelerated the game's worldwide reach, particularly through U.S. military personnel stationed in Japan during the occupation. Articles in the Army's Stars and Stripes newspaper, such as those from 1952, 1954, and 1956, highlighted jan-ken among G.I.s, who brought the game back home and integrated it into everyday American life.^[3] This period saw its proliferation via pop culture, including 1950s television shows that featured it in comedic or decision-making scenes, solidifying its status as a universal icebreaker and conflict resolver across continents. In the 21st century, digital platforms have dramatically boosted accessibility, with mobile apps and online multiplayer versions enabling global play without physical proximity. The World Rock Paper Scissors Association, founded in 2015, has organized virtual tournaments and developed apps that connect players worldwide, turning the game into a competitive e-sport with millions of users.^[23]

Strategies

Skill-based approaches

Skill-based approaches in rock-paper-scissors rely on human players' ability to observe and exploit non-random behaviors in opponents, turning the game from pure chance into one influenced by psychological insight. One key tactic involves reading opponent patterns, such as tendencies to overuse a particular gesture after a win or in specific contexts. For instance, empirical analysis of over 2.6 million matches reveals that players frequently select rock as their first move at a rate of 34.0%, paper at 34.8%, and scissors at 31.2%, allowing observant players to counter these biases by anticipating common choices like paper in opening rounds.^[24] Similarly, players often repeat a winning gesture, creating exploitable streaks that skilled opponents can target by selecting the counter-gesture.^[24] Bluffing and misdirection further enhance these observational skills by introducing deliberate deception to manipulate an opponent's expectations. Experienced players may feign hesitation or subtle body language cues, such as a slight fist clench suggesting rock while intending scissors, to provoke predictable reactions based on reverse psychology.^[25] This tactic leverages the human aversion to perceived predictability, as opponents adjust their choices to avoid what they believe is being anticipated, thereby opening opportunities for the bluffer to capitalize on the induced error.^[25] Conditional probability plays a central role in adapting to prior rounds, where players adjust selections based on recent outcomes to disrupt patterns. A common strategy is to avoid repeating the last winning move of the opponent, instead choosing the gesture that would have beaten it, as losers tend to shift clockwise (rock to scissors, scissors to paper, paper to rock) after a loss.^[24] This "win-stay, lose-shift" heuristic, observed in human play, involves sticking with a successful choice while changing after defeat, enabling players to predict and counter shifts with about 53% responsiveness to historical throws.^[24] Empirical studies from large-scale human gameplay demonstrate tangible advantages from these pattern recognition tactics. Analysis of a million rock-paper-scissors games indicates that experienced players, by exploiting opponent histories, achieve win rates of 34.65% compared to the random baseline of 33.33%, with best-response strategies yielding expected payoffs of approximately 0.14 per game through effective conditional adjustments.^[24] Further research on opponent modeling confirms that humans gain significant information from simple sequential dependencies, such as prior moves, outperforming random play in 58 dyads by exploiting these patterns, though complex dependencies yield diminishing returns after accounting for basics.^[26]

Computational analysis

Rock-paper-scissors is a finite, symmetric, zero-sum game that admits a unique mixed-strategy Nash equilibrium, where each player randomizes their choice of rock, paper, or scissors with equal probability of \frac{1}{3}.^[27] In this equilibrium, no player can improve their expected payoff by unilaterally deviating from the strategy, as the opponent's randomization ensures an average payoff of zero (one-third win, one-third loss, one-third tie) regardless of the deviator's pure strategy.^[27] This equilibrium, first formalized by John Nash in his 1950 dissertation, exemplifies how randomization prevents exploitation in non-cooperative games with cyclic dominance.^[27] Markov chains provide a probabilistic framework for modeling and predicting opponent moves in iterated play, treating each gesture as a state in a sequence where the probability of the next state depends only on the current one.^[28] The transition matrix captures empirical frequencies from opponent history; for instance, if scissors follows rock with probability 0.4, paper with 0.3, and rock with 0.3, the chain forecasts the next move to counter the most likely outcome.^[29] Higher-order chains extend this by conditioning on multiple prior states, enabling adaptation to patterns in non-random human play, though short memory lengths (order 1–5) suffice to exploit typical dependencies.^[28] AI implementations leverage these models to surpass human performance in repeated games. In a 2020 study, a multi-agent system using ensembles of first- to tenth-order Markov chains achieved win rates exceeding 60% against 52 human opponents over 300 rounds, by dynamically selecting the best predictor based on recent history (focus length of 5–10 rounds).^[28] This approach exploits human biases toward short-term patterns, yielding scores like 198 wins, 55 ties, and 47 losses in aggregate, demonstrating robust prediction without assuming perfect randomness.^[28] More recent research, such as a 2024 study on repeated play against bots, highlights limits in human adaptive learning, informing further AI advancements in modeling non-equilibrium behaviors.^[30] Game theory applications highlight rock-paper-scissors as a model of non-transitive preferences, where the dominance relation forms a cyclic tournament: rock beats scissors, scissors beat paper, and paper beats rock, creating no overall superior strategy.^[27] In graph-theoretic terms, this is a regular tournament on three vertices, a directed cycle where each option has out-degree 1, illustrating intransitivity in decision-making and evolutionary dynamics.^[31] Such structures underpin analyses of balanced multi-player games and non-hierarchical competitions.^[31]

Variations

Rule changes

Rule changes in rock paper scissors variants modify the procedural aspects of gameplay, such as the number of rounds, participant involvement, revelation timing, and consequences for errors, while preserving the core dominance cycle where rock crushes scissors, scissors cut paper, and paper covers rock. These alterations extend play duration, incorporate multiple players, introduce elements of speed or surprise, and enforce stricter conduct to enhance fairness or excitement in competitive or group settings.^[32] Extended formats like best-of-five or best-of-three series require players to win a majority of multiple rounds, often replaying ties to determine a clear victor, which prolongs matches and reduces reliance on single outcomes. For instance, in organized tournaments, preliminary rounds may use a best-of-three structure, escalating to best-of-five in finals to heighten stakes and test consistency. Elimination tournaments build on this by having winners advance through successive single-round or series matches, with losers eliminated until a champion remains, commonly used in large-group events to efficiently crown a winner.^[33]^[34] Group versions adapt the game for multiple participants by employing simultaneous reveals where all players show gestures at once and ties are replayed, or team relays in which squad members play sequentially to accumulate wins for advancement. In team competitions, groups of three might contest via parallel best-of-three individual matches, with the first team securing two victories progressing, fostering collaboration and strategy among allies. Winner-stays-on formats allow the victor to remain and face rotating challengers, creating dynamic chains of play in casual gatherings.^[32]^[33]^[35] Timed reveals incorporate synchronized counting cadences, such as "one, two, three, shoot," to ensure simultaneous gestures and prevent anticipation advantages, with variations delaying revelation for one player to add uncertainty. False starts during this timing—revealing prematurely—incur penalties like round redos on first offense or automatic losses on repeats, maintaining game integrity in formal play.^[32] Penalty rules address infractions beyond gestures, such as repeated procedural errors; for example, consecutive false starts may disqualify a player from the match. These mechanisms vary by context but aim to deter disruptions and ensure equitable progression.^[32]

Expanded gestures

One prominent expansion of the traditional rock paper scissors game introduces two additional gestures—lizard and Spock—creating a five-gesture variant known as rock-paper-scissors-lizard-Spock. Invented by Sam Kass and Karen Bryla in the early 1990s, this version maintains the non-transitive cycle by having each gesture defeat exactly two others and lose to the remaining two, reducing the probability of ties to 20% compared to 33% in the standard game.^[36] The rules specify that scissors cut paper and decapitate lizard; paper covers rock and disproves Spock; rock crushes scissors and lizard; lizard poisons Spock and eats paper; and Spock smashes scissors and vaporizes rock. This variant gained wider attention following a 2005 mention in The Times of London, though it achieved mainstream popularity through its depiction in the television series The Big Bang Theory in 2008.^[37] Regional and cultural adaptations sometimes incorporate new gestures to reflect local themes or elements, such as the addition of "gun" in certain informal variants. In one such expansion, gun defeats rock, scissors, and other conventional gestures by overpowering them, but it loses to water, which rusts it, preserving a balanced cycle.^[38] Similarly, water interacts non-transitively by eroding rock, extinguishing fire (if added), and rusting gun or scissors, while being absorbed by sponge or evaporated by air in broader sets. These additions aim to extend the game's thematic relevance without disrupting the core intransitive logic.^[38] Themed versions popular among children often substitute or add playful gestures drawn from imagination or media, such as "dinosaur," which crushes scissors by devouring or stomping them while losing to paper that wraps it or rock that withstands it. In educational card games like Rock Paper Saurus, dinosaur-themed cards follow rock-paper-scissors principles, where specific dinosaurs "beat" others based on prehistoric attributes, such as a larger predator overpowering a smaller one, fostering learning about Mesozoic era species.^[39] Balance in these expansions relies on preserving non-transitive properties, where no gesture universally dominates, forming cyclic dominance (e.g., A beats B, B beats C, C beats A) to ensure fairness and strategic depth. For odd-numbered gesture sets like five or seven, designers typically structure interactions so each option defeats exactly half the others (rounded down) and loses to the rest, avoiding transitive hierarchies that could favor one choice.^[38] This approach, evident in variants with 15 gestures including gun and water, yields 105 possible outcomes per matchup, each with equal win probabilities under random play, as analyzed in game theory extensions of the original model.^[40]

Analogues

Biological examples

In the side-blotched lizard (Uta stansburiana), male throat color morphs exhibit a cyclic dominance pattern analogous to rock-paper-scissors, where orange-throated males aggressively defend multiple territories and females, outcompeting blue-throated males who focus on mate-guarding but are vulnerable to yellow-throated sneaker males that exploit unguarded nests, only for orange males to then dominate the yellows through superior territorial control.^[41] This three-strategy system, studied extensively in the 1990s, demonstrates frequency-dependent selection maintaining polymorphism, as each morph's success cycles based on the relative abundances of the others, preventing any single strategy from fixating in the population.^[42] Barry Sinervo's field experiments in California confirmed these dynamics, showing population cycles over generations that mirror the game's intransitive relations.^[41] Bacterial communities provide another biological parallel, as seen in engineered and natural strains of Escherichia coli where cyclic antagonism enforces rock-paper-scissors-like interactions. In one seminal setup, three strains form a loop: a toxin-producing strain kills a sensitive strain, the sensitive strain resists a different toxin from the resistant strain, and the resistant strain falls prey to the first toxin's effects, leading to oscillatory population dynamics in vitro and in vivo. This non-transitive competition, first demonstrated in 2002, promotes coexistence and biodiversity by preventing dominance, with spatial structure and resource gradients influencing cycle stability.^[43] Subsequent studies have replicated these patterns in microfluidic devices, highlighting how such cycles enhance overall community productivity compared to transitive hierarchies.^[44] Evolutionary game theory elucidates cyclic dominance in animal behavior through models like the hawk-dove game, extended to predator-prey contexts where strategies form intransitive loops. In the classic hawk-dove framework, aggressive "hawk" individuals risk injury against other hawks but dominate "dove" pacifists, while doves avoid costly fights; when integrated into multi-species predator-prey systems, this evolves into rock-paper-scissors cycles, such as aggressive predators exploiting passive prey, which in turn evade sneaky predators that falter against aggressors. These models, originating in the 1970s, predict stable polymorphisms in behaviors like territorial defense or foraging, as observed in various avian and mammalian conflicts where no strategy universally prevails. Seminal work by John Maynard Smith formalized how such games maintain diversity via negative frequency dependence, akin to natural RPS equilibria. A 2017 experimental study trained captive chimpanzees (Pan troglodytes) to play rock-paper-scissors using touchscreen prompts with icons for rock (fist), paper (open hand), and scissors (two fingers), achieving success rates comparable to human four-year-olds after extensive training and demonstrating comprehension of the cyclic rules. This capacity suggests an innate potential for non-transitive reasoning in gestural communication, paralleling the game's logic in resolving conflicts or play without linear hierarchies.^[45]

Mechanical and geometric models

Mechanical models of rock paper scissors encompass engineered systems designed to replicate the game's physical gestures and decision-making processes through robotics and automation. These implementations often integrate sensors, actuators, and control algorithms to simulate human-like interactions, providing platforms for studying human-robot cooperation and rapid response dynamics. A seminal robotic implementation is the Janken robot, developed in 2012 by researchers at the Ishikawa Group Laboratory, University of Tokyo. This system employs high-speed computer vision to recognize an opponent's hand gesture—rock, paper, or scissors—in approximately 1 millisecond using a specialized vision chip processing at 1000 frames per second. Upon detection, the robot selects and executes the countering gesture via a five-fingered robotic hand equipped with pneumatic actuators, forming the shape in 10–20 milliseconds to ensure it "wins" every round with 100% accuracy against human players. The design emphasizes synchronized human-machine timing, where the robot's speed exploits the typical 20–30 millisecond human reaction delay, demonstrating practical applications in predictive interaction systems.^[46] Geometric models abstract the non-transitive dominance relations of rock paper scissors into mathematical structures, capturing the cyclic nature where no single gesture universally dominates. In graph theory, the game is represented as a directed tournament graph with three vertices corresponding to rock, paper, and scissors, and edges indicating dominance: rock → scissors, scissors → paper, and paper → rock, forming a complete directed cycle without transitive closure. This structure illustrates the game's zero-sum symmetry and has been analyzed for properties like Nash equilibria in mixed strategies, where each gesture is played with equal probability (1/3) to achieve balance. Such models extend to larger tournaments, generalizing rock paper scissors to n-player variants while preserving cyclic intransitivity.^[47] Further geometric constructions explore non-transitive cycles through self-similar and fractal-inspired patterns, particularly in extensions beyond the basic three gestures. For instance, nontransitive dice sets—analogous to rock paper scissors in their cyclic winning probabilities—can be constructed with nested relations based on numerical progressions, yielding self-similar structures where smaller cycles replicate larger ones fractally. These models, derived from magic square arrangements like the Lo Shu, demonstrate how dominance hierarchies scale hierarchically, with each "level" forming a rock-paper-scissors-like subunit that beats the previous but loses to the next, enabling infinite regress of non-transitive relations. This approach highlights geometric recursion in modeling balanced, unpredictable competitions.^[48]

Real-World Uses

Decision-making applications

Rock-paper-scissors has been employed in formal legal settings to resolve impartial disputes when parties cannot agree. In 2006, U.S. District Judge Gregory A. Presnell in the Middle District of Florida ordered attorneys in the case Avista Management, Inc. v. Wausau Underwriters Insurance Co. to play a single game of rock-paper-scissors at a neutral site to determine the venue for a corporate representative's deposition, citing the attorneys' inability to agree on basic procedural details.^[4] The order specified that the winner would choose the location, with an appeal option scheduled if disputed, highlighting the game's role as a simple, binding tiebreaker in litigation.^[49] This unconventional approach garnered international media attention and was praised by the Florida Bar for efficiently advancing judicial proceedings amid attorney discord.^[50] In the commercial sector, rock-paper-scissors has facilitated high-stakes business decisions requiring neutrality. In 2005, the Japanese electronics firm Maspro Denkoh Corporation, facing an impasse on selecting an auction house for its $20 million art collection—including works by Cézanne and Picasso—required representatives from Christie's and Sotheby's to compete in the game.^[51] Christie's emerged victorious when its executive chose scissors, defeating Sotheby's paper, thereby securing the exclusive consignment rights; the collection ultimately sold for over $22 million at Christie's.^[52] This instance demonstrated the game's utility in resolving vendor selection disputes without bias, influencing the ordering and marketing of auction lots.^[53] Beyond isolated high-profile cases, rock-paper-scissors serves as a tool for random selection in corporate environments, particularly during the 2010s. Companies have integrated it into team-building activities to make impartial choices, such as assigning project roles or breaking ties in group decisions, fostering collaboration through its quick and equitable nature.^[54] For example, in professional development sessions, participants use the game to randomly determine speaking orders or task allocations, ensuring no favoritism and enhancing group dynamics.^[55] From a psychological perspective, rock-paper-scissors promotes perceived fairness in decision-making due to its symmetric probabilities, where each gesture has an equal 1/3 chance of winning, tying, or losing against opponents' choices.^[56] This perceived equity stems from the game's zero-sum structure, which aligns with principles of probabilistic justice, making it suitable for institutional applications where trust in impartiality is essential.^[57]

Cultural and behavioral instances

In a notable instance in women's soccer, a referee in the English FA Women's Super League used rock-paper-scissors to determine the kickoff during a 2018 match between Manchester City and Reading, after forgetting his coin; the official, David McNamara, was subsequently suspended for three weeks by the Football Association for not acting in the best interests of the game.^[58] This event highlighted the game's occasional informal adoption in sports settings as a quick tiebreaker, though it drew criticism for deviating from standard protocols.^[59] Rock-paper-scissors has been integrated into video game design to create balanced, strategic mechanics, particularly in the Pokémon series since the 1990s, where the core type matchups—such as fire beating grass, grass beating water, and water beating fire—emulate the game's intransitive cycle to influence battle outcomes and encourage tactical choices.^[60] This rock-paper-scissors-inspired system, introduced in the original 1996 games, extends across 15 initial types and has evolved into a foundational element of Pokémon's competitive play, promoting depth without relying solely on power levels.^[61] In popular culture, rock-paper-scissors frequently appears in films and online memes as a symbol of spontaneous decision-making or humor, with viral examples including Dwayne Johnson's 2018 recreation of a meme where he always chooses "rock" due to his nickname, amplifying the game's lighthearted, relatable appeal across media.^[62] Such references underscore its global ubiquity, from comedic resolutions in movies to internet humor depicting everyday dilemmas, reinforcing its role as a universal, non-verbal communicator in entertainment.^[63]

Competitive Play

Organizations

The competitive aspect of rock paper scissors has been elevated by several organizations dedicated to standardizing rules, hosting events, and fostering a global community of players. These groups have played a pivotal role in transforming the game from a casual pastime into a recognized esport with structured competitions. The World Rock Paper Scissors Society, founded in 2002 in Toronto, Canada, by brothers Douglas and Graham Walker, emerged as a pioneering body for promoting rock paper scissors as a competitive sport.^[64] The society focused on developing official rules to ensure fair play, including guidelines on gesture timing, tiebreakers, and tournament formats, which helped legitimize the game internationally.^[65] It organized annual world championships from 2002 to 2009, attracting hundreds of participants and drawing media attention to the strategic depth of the game.^[64] In the United States, the USA Rock Paper Scissors League (USARPS) was established in the mid-2000s to promote the sport domestically through high-profile events and sponsorships.^[66] Launched with its inaugural national championship in 2006 in Las Vegas, Nevada, the league partnered with Bud Light to offer significant prizes, such as $50,000 for the winner, and broadcast events on networks like ESPN to build public interest.^[67] The USARPS emphasized professional-level competition, including qualifiers and a points system, contributing to the growth of regional tournaments across the country.^[66] The World Rock Paper Scissors Association (WRPSA), founded in 2015 in Ottawa, Canada, serves as a key international hub for rules enforcement, player rankings, and event organization.^[68] The WRPSA maintains an official rulebook, hosts virtual and in-person tournaments as of 2025, and promotes inclusivity by supporting competitions in multiple countries, ensuring consistent governance for international play.^[68] Regional organizations have also proliferated to localize promotion and events. For example, in the United Kingdom, the first national rock paper scissors championship was held in 2007 in Rhayader, Powys, followed by a second in 2008, organized by dedicated local groups to build grassroots participation and adapt rules to British contexts.^[69] Similar bodies in other regions focus on cultural integration and community tournaments while aligning with global standards set by bodies like the WRPSA.^[70]

Major tournaments

The World Series of Rock Paper Scissors, organized annually by the World Rock Paper Scissors Society in Toronto, Canada, began in 2002 and attracted international competitors through qualifiers from various countries. The event featured a single-elimination bracket format culminating in finals at a brewery venue, with a total prize pool of C$10,000, including C$7,000 for the champion and smaller amounts for runners-up. It concluded after the 2009 edition, which drew over 500 participants.^[64]^[71]^[72] In the United States, the Bud Light-sponsored USA Rock Paper Scissors League (USARPS) Championships ran from 2006 to at least 2008, emphasizing professional-level play with regional qualifiers feeding into national finals at the Mandalay Bay Resort in Las Vegas, Nevada. The format involved best-of-three matches in a knockout tournament, broadcast on ESPN, and offered a $50,000 grand prize to the winner, drawing hundreds of entrants annually. Notable champions included Mario Anastasov in 2006, Jamie Langridge in 2007, and Sean Sears in 2008.^[67]^[73] Guinness World Records recognizes several milestones in rock paper scissors competitions, including the largest tournament with 2,950 participants, achieved by Oomba, Inc. at Gen Con in Indianapolis, Indiana, on August 17, 2014. This event used a bracket system to determine a single winner amid the gaming convention's activities. A subsequent record for the most participants in a single competition was set at 10,033 by Tianjin Joy City in China on December 24, 2021, spanning four days to mark the mall's anniversary.^[74] Media-driven events have popularized large-scale rock paper scissors play, such as the "Jackpot En Poy" segment on the Philippine variety show Eat Bulaga!, where contestants compete in rock paper scissors for escalating cash jackpots, often reaching millions of pesos, as part of the program's noontime broadcasts since the early 2010s.

References

[1]
The Long, Winding History of Rock Paper Scissors
Mar 4, 2020 · The author refers to it as shoushiling and dates its origins to some time during the Chinese Han dynasty (206 BC - 220 AD).Missing: credible | Show results with:credible
[2]
[PDF] Evidence from a Million Rock-Paper-Scissors Games
May 14, 2014 · Rock-Paper-Scissors, also known as Rochambeau and jan-ken-pon, is said to have originated in the Chinese Han dynasty, making its way to Europe ...Missing: origins | Show results with:origins
[3]
Rock Paper Scissors | TeachingHistory.org
Another mention of the supposed historical connection with Rochambeau is in physicist Len Fisher's Rock, Paper, Scissors: Game Theory in Everyday Life (2008):.Missing: rules credible
[4]
The Official History of Rock Paper Scissors
Rock Paper Scissors history begins in ancient China, moves through early Japanese hand games, and becomes modern janken before spreading worldwide in the.
[5]
How rock, paper, scissors started in ancient China - Fridayeveryday
Mar 4, 2024 · The game of rock, paper, scissors started in China, historians believe. The Ming Dynasty writer Xie Zhaozhe wrote in the 1600s that it date back to the Han ...
[6]
How to play Rock Paper Scissors in Japanese - じゃんけん (Janken)
Janken is the Japanese version of rock-paper-scissors, a hand game where players simultaneously form one of three shapes with their hand: rock (グー, “gū”), ...
[7]
Japan's Most Dangerous Game: Rock, Paper, Scissors - Tofugu
Jul 6, 2012 · Janken is played pretty similarly to the way most people play rock, paper, scissors in the US: you use one of three moves to beat your opponent.
[8]
石头剪子布 - (Shítou jiǎnzi bù) - China - Mama Lisa's World
"石头剪子布" (Shítou jiǎnzi bù) is the Mandarin version of "Rock, Paper, Scissors". It's used to decide something between two people, such as who goes first ...
[9]
Rock-Paper-Scissors - Chinese Culture - eChineseLearning
Nov 27, 2013 · Rock-Paper-Scissors is a hand game that helps kids to learn Chinese while having fun. Got questions? Take a FREE 1-on-1 online Chinese ...
[10]
South Korea - 가위 바위 보 - Mama Lisa's World
Kai (scissors), Bai (rock), Bo (paper) is a choosing game used to decide something between two kids. It's the Korean version of "Rock, Paper, Scissors".
[11]
Learning French: Five fun ways to make a decision in France
Jun 9, 2025 · ... French version of 'rock-paper-scissors'. The invisible items whipped out of the air with one hand are 'pierre, papier/feuille, ciseaux ...
[12]
Piedra, papel o tijera - Spanish Children's Songs - Mama Lisa's World
"Piedra, papel o tijera" is a Spanish version of "Rock, Paper, Scissors". It's used to decide something between two people, such as who goes first in a game.
[13]
The Fascinating Variations of Rock Paper Scissors Around the World
Dec 11, 2022 · Indonesia and Malaysia, batu, gunting, kertas. Rock, scissors, paper. A local bird, water, stone trio also exists and keeps the same loop.
[14]
Official Rock Paper Scissors Rules | WRPSA Regulations
Only three throws are permitted: Rock, Paper, and Scissors. Any other gesture is an illegal throw. Rock: Closed fist with thumb flat across fingers. Paper: Open ...
[15]
How to Play Rock Paper Scissors
The Basic Rules of RPS ... Players reveal their gestures simultaneously after counting down using “Rock, Paper, Scissors, Shoot” or “1, 2, 3, Shoot.” This ensures ...
[16]
Rock Paper Scissors Relay or Roshambo Relay - Playworks
Before You Start. Divide into two groups; each group in a single file line. Each line of players starts at the ends of the “U”. Review how to play Rock ...
[17]
Official Rock Paper Scissors Rules – WRPSA Guide to Play ...
Sep 20, 2025 · Best-of Rounds: Standard matches are best‑of‑3 rounds (first to 2 wins). Organizers may use longer formats (best‑of‑5, best‑of‑7, etc.) for ...
[18]
[PDF] Non-transitivity and Probability - WyoScholar
▻ A simple example of non-transitivity is rock-paper-scissors. Rock beats scissors, scissors beats paper, but rock does not beat paper! In fact paper beats rock ...Missing: "academic | Show results with:"academic
[19]
[PDF] The Nontransitive Dice: New Results for a Statistical Paradox in a ...
Mar 1, 2024 · P ≻ R is true, meaning that Rock, Paper,. Scissors is an example of a nontransitive game. The winning results in the game form a cyclical ...Missing: "academic | Show results with:"academic
[20]
[PDF] Rock, Paper, Scissors Probability
What is happening? Each choice of rock, paper or scissors should be normalized to 1 with equal probability. Theoretically, they would be equally likely, so ...Missing: conditions "academic
[21]
Janken: The Japanese version of rock-paper-scissors - Hanabira.org
Origins of Janken. The origins of Janken are not entirely clear, but it is believed to have originated in China and spread to Japan during the Edo period.<|separator|>
[22]
Rock Paper Scissors | Official Rules, Tournaments & World ...
Matches are often first to 2 wins or best 2 of 3 in tournament. In the Finals it is usually first to 3 wins or best 3 of 5.How to Play · About · World Rock Paper Scissors Day · The Official History of Rock...
[23]
https://wrpsa.com/
[24]
The Psychological Depths of Rock-Paper-Scissors
Jul 11, 2023 · Rock-paper-scissors is a game of player unpredictability in its purest form, for this single factor is the sole determinant of the game's uncertainty.Missing: empirical patterns 1990s
[25]
Formalizing Opponent Modeling with the Rock, Paper, Scissors Game
Sep 16, 2021 · Here, we offer a novel framework for formally describing and quantifying human adversarial reasoning in the rock, paper, scissors game.
[26]
Why Winning in Rock-Paper-Scissors (and in Life) Isn't Everything
Apr 2, 2018 · The theory behind such stable strategy profiles, which came to be known as “Nash equilibria,” revolutionized the field of game theory, altering ...
[27]
Multi-AI competing and winning against humans in iterated Rock ...
Aug 17, 2020 · Thus, for the next round, AI-2 has 1/3 probability to select Paper, Scissors and Rock. Table 2 shows an example for the selection between AI ...
[28]
Rock Paper Scissors Playing the Game with Markov Chains
Rock Paper Scissors Playing the Game with Markov Chains · N. Pomerleau · Published 2013 · Computer Science, Mathematics.
[29]
Rock, Paper, Scissors, Etc -- Topics in the Theory of Regular ... - arXiv
Jun 29, 2018 · We survey the properties of regular tournaments, which we will call games. In the process we describe a number of constructions for such games.
[30]
Rock Paper Scissors Variations
Variations add moves, scoring systems, or formats to the classic game. This guide covers fair design, timing, group play, and coding options.
[31]
Rock Paper Scissors Official Rules - MOKB Presents
For those new to the game, the only acceptable throws are Rock, Paper and Scissors. Any use of Dynamite, Bird, Well, Spock, Water, Match, Fire, God, Lightning, ...
[32]
Rock, Paper, Scissors (Tournament) - SessionLab
Play "Rock, Paper, Scissors" against each other until the first win. 3. The winner has to find a new opponent. The losing player becomes a fan of the winner. 4.
[33]
[PDF] Extreme Rock, Paper, Scissors
Have each member of the group pair up for the first round of rock, paper, scissors. If there is an odd number, add the odd person out to another pair and ...
[34]
Rock Paper Scissors Spock Lizard
NFT: Original Image for Rock Paper Scissors Lizard Spock NFT - Current owner: Steve Koenig - The original GIF of the image above from the early 1990's, signed ...
[35]
What is Rock Paper Scissors
Lizard poisons Spock and eats paper. It is crushed by rock and decapitated by scissors. This variant was mentioned in a 2005 article in The Times of London and ...
[36]
RPS - 15 - umop.com
WATER DROWNS DEVIL & DRAGON, ERODES ROCK, PUTS OUT FIRE, RUSTS SCISSORS & GUN, CONDUCTS LIGHTNING. DRAGON COMMANDS DEVIL, BREATHES LIGHTNING & FIRE, RESTS ...Missing: Asian | Show results with:Asian
[37]
https://wrpsa.com/what-is-rock-paper-scissors/
[38]
Math Horizons April 2017: What Nontransitive Dice Exist Among Us?
May 5, 2017 · As children we played rock-paper-scissors (RPS) to determine who went first or who got the last cookie. RPS is an example of a nontransitive ...Missing: gestures | Show results with:gestures
[39]
The rock–paper–scissors game and the evolution of alternative male ...
Mar 21, 1996 · We report here the application of an evolutionary stable strategy model to a three-morph mating system in the side-blotched lizard.
[40]
Polygyny, mate-guarding, and posthumous fertilization as alternative ...
We use nuclear microsatellites to estimate the paternity rates of three male lizard strategies previously modeled as a rock-paper-scissors game.
[41]
Rock-paper-scissors: Engineered population dynamics increase ...
Sep 6, 2019 · The resulting “rock-paper-scissors” dynamic demonstrates rapid cycling of strains in microfluidic devices and leads to an increase in the ...
[42]
Janken (rock-paper-scissors) robot with 100% winning rate (human ...
In this research we develop a janken (rock-paper-scissors) robot with 100% winning rate as one example of human-machine cooperation systems.
[43]
[PDF] Nash Equilibria of Rock Paper Scissors Variants - arXiv
Oct 16, 2024 · Abstract. We generalize Rock Paper Scissors to complete directed graphs, or tournaments, on n vertices. Properties of the mixed-strategy ...
[44]
[2311.12811] Self-Similar Structures of Nontransitive Dice Sets - arXiv
Sep 20, 2023 · Nontransitive dice are dice beating one another in a cyclic way: die A wins die B, B wins C, and C wins A (like in a rock-paper-scissors game).
[45]
Judge Rules Dispute to Be Settled By 'Rock, Paper, Scissors' Match
Jun 7, 2006 · The judge's order states that the game will take place on June 20, 2006, at 4 p.m. at a "neutral site." If the two attorneys can't agree on a ...
[46]
Judge: 'Rock, paper, scissors' to decide dispute - NBC News
Jun 9, 2006 · Judge: 'Rock, paper, scissors' to decide dispute. A judge in Tampa, miffed at the inability of attorneys to agree on even the slightest details ...
[47]
'Rock, paper, scissors' order garners worldwide attention
Jul 1, 2006 · At issue was the childlike squabbling between the attorneys in Avista Management, Inc., vs. Wausau Underwriters Insurance Co. (case no. 6:05-cv- ...
[48]
Rock, Paper, Payoff: Child's Play Wins Auction House an Art Sale
Apr 29, 2005 · An ancient method of decision-making that has been time-tested on playgrounds around the world: rock breaks scissors, scissors cuts paper, paper smothers rock.Missing: 2013 lot ordering
[49]
How a game of rock, paper, scissors decided a $20 million auction ...
When a Japanese company couldn't decide which auction house to sell its art collection through, it put the decision in the auctioneers' hands.Missing: 2013 ordering
[50]
When Christie's and Sotheby's Played Rock, Paper, Scissors ... - Artsy
Aug 7, 2019 · When A Game of Rock, Paper, Scissors Decided a $20-Million Auction Consignment ... lot of the house's May 4th evening sale, fetching $11.8 million ...Missing: 2013 | Show results with:2013
[51]
https://www.nytimes.com/2005/04/29/arts/design/rock-paper-payoff-childs-play-wins-auction-house-an-art-sale.html
[52]
Icebreaker: Rock Paper Scissors Extreme | GUIDE, Inc.
Sep 28, 2015 · Make sure everyone knows how to play, and set up the group for success by indicating that they are going to say, “rock, paper, scissors, shoot” ...
[53]
[PDF] A Fair Game? The Case of Rock, Paper, Scissors
This game also provides a rich context to explore the relationship between experimental and theoretical probabil- ity through the concept of a fair game.
[54]
A study of probability and fairness understanding through games
Oct 18, 2025 · This study aims to explore the concept of probabilistic justice and its impact on elementary school students' understanding of fairness.
[55]
Rock, paper, scissors - Mathematics Hub
How do you perceive the fairness of the game? Why might some people feel they have an equal chance or not? How would you calculate the probability of ...
[56]
Referee suspended over using rock, paper, scissors instead of coin ...
Nov 14, 2018 · Referee David McNamara has been suspended for three weeks after overseeing a bizarre start to a Women's Super League game last month.Missing: 2019 | Show results with:2019
[57]
Referee David McNamara suspended for 'rock, paper, scissors' - BBC
Nov 13, 2018 · ... rock, paper, scissors instead of a coin toss. David McNamara made the ... Related internet links. FA Women's Super League. The BBC is not ...
[58]
5 Game Design Decisions That Made the Original Pokémon Games ...
Apr 4, 2016 · Pokémon may not be the only or even the first video game to implement an elemental rock-paper-scissors system in its combat, but its ...
[59]
History of Pokémon, Part Two: Generation I (Red/Blue/Yellow)
Dec 31, 2018 · ... rock-paper-scissors style typing system. Fire beats grass, grass beats water, water beats fire, and so on. There is a total of fifteen types ...
[60]
Learning the rules of the rock-paper-scissors game: chimpanzees ...
Aug 10, 2017 · The present study aimed to investigate whether chimpanzees (Pan troglodytes) could learn a transverse pattern by being trained in the rules ...Missing: gestural 2010s
[61]
Chimpanzees learn rock-paper-scissors | KYOTO UNIVERSITY
Aug 24, 2017 · The findings show that chimpanzees can learn the circular pattern at the heart of the game. Although, it took them significantly longer to learn ...Missing: gestural 2010s
[62]
A Cultural History of Rock-Paper-Scissors - The Atlantic
Dec 23, 2015 · Versions of rock-paper-scissors can be found in cultures around the world, but outside of North America it remains most ubiquitous in Asia.
[63]
Dwayne Johnson does the rock, paper, scissor meme - Getty Images
Apr 13, 2018 · Dwayne Johnson recreates his rock paper scissors meme at the press junket for his new film Rampage, in London.Missing: culture | Show results with:culture
[64]
Inside the World of Professional Rock Paper Scissors - Priceonomics
Apr 26, 2016 · In our conversation with Rosh, we brought up academic studies by researchers who claim to have found the optimum strategy for playing RPS.Missing: format | Show results with:format
[65]
Rock, Paper, Scissors: High Drama in the Tournament Ring
Sep 5, 2004 · This was tournament-style Rock Paper Scissors, in which the stakes are high, and expert players do well over time only because of skill and hard work.Missing: documented literature<|separator|>
[66]
ESPN.com: Page 2 : Rock, paper, scissors? Beer!
The experience convinced them that the sport could produce poker-esque ratings, so they created their own league from scratch: the USA Rock, Paper, Scissors ...
[67]
Bud Light/USA Rock Paper Scissors League Championship Offers ...
Mar 5, 2008 · A new Bud Light USARPS League champion will be crowned on Sunday, June 22 at Mandalay Bay Hotel & Casino in Las Vegas.
[68]
About WRPSA | World Rock Paper Scissors Association
Founded in Ottawa in 2015, the organization celebrates a game that crosses cultural boundaries and requires no special equipment.Missing: 1997 Canada
[69]
Rock–Paper–Scissors - Encyclopedia.pub
Oct 25, 2022 · By the early 20th century, rock–paper–scissors had spread beyond Asia, especially through increased Japanese contact with the west. Its English- ...
[70]
Rock Paper Scissors Tournaments | WRPSA Events
Regional and National Events These events bring together top players from across cities and regions. Winners qualify for even larger events and earn higher ...
[71]
8th Rock Paper Scissors World Championships in Toronto
Oct 12, 2009 · The tournament, organised by the sport's governing body World RPS, sees a total of $10,000 prize money up for grabs with a grand prize of $7,000 ...
[72]
Hundreds to compete for rock, paper, scissors title | Reuters
Aug 9, 2007 · Top players from around the globe will gather in Toronto this weekend to compete for a C$10,000 (4,636 pounds) prize and the title of world ...
[73]
Sean Sears Crushes The Competition At Third Annual Bud Light ...
Jun 22, 2008 · Sean Sears, 23, of Chicopee, Mass. emerged from hand-to-hand combat with more than 300 of the nation's finest Rock Paper Scissors players to claim the 2008 Bud ...
[74]
Largest Rock, Paper, Scissors tournament | Guinness World Records
The largest Rock, Paper, Scissors competition consists of 10,033 participants, and was achieved by Tianjin Joy City (China) in Tianjin, China, on 24 December ...Missing: 2009 | Show results with:2009