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Rock paper scissors
Rock paper scissors
from Wikipedia
Rock paper scissors
GenresHand game
Players2 (or more)
Setup timeNone
Playing timeseconds
ChanceHigh

Rock paper scissors (also known by several other names and word orders) is an intransitive 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 closed fist: ✊), "paper" (a flat hand: ✋), and "scissors" (a fist with the index finger and middle finger extended, forming a V: ✌️). The earliest form of a "rock paper scissors"-style game originated in China and was subsequently imported into Japan, where it reached its modern standardized form, before being spread throughout the world in the early 20th century.[citation needed]

A simultaneous, zero-sum game, it has three possible outcomes: a draw, a win, or a loss. A player who decides to play rock will beat another player who chooses scissors ("rock crushes scissors" or "breaks scissors" or sometimes "blunts scissors"[1]), but will lose to one who has played paper ("paper covers rock"); a play of paper will lose to a play of scissors ("scissors cuts paper"). If both players choose the same shape, the game is tied, but is usually replayed until there is a winner.

Rock paper scissors is often used as a fair choosing method between two people, similar to coin flipping, drawing straws, or throwing dice in order to settle a dispute or make an unbiased group decision. Unlike truly random selection methods, however, rock paper scissors can be played with some degree of skill by recognizing and exploiting non-random behavior in opponents.[2][3]

Names

[edit]

The modern game is known by several other names such as Rochambeau, Roshambo, Ro-sham-bo, Bato Bato Pik, and Jan-ken-pon.[4][5][6] While the game's name is a list of three items, different countries often have the list in a different order.

In North America and the United Kingdom, it is known as "rock, paper, scissors" or "scissors, paper, stone".[7][8] If this name is chanted while actually playing the game, it might be followed by an exclamation of "shoot" at the moment when the players are to reveal their choice (i.e. "Rock, paper, scissors, shoot!").[9]

There have been claims that there are regional variations of the name in Australia; one video claimed that it was referred to as "scissors, paper, rock" in New South Wales, "rock, paper, scissors" in Victoria, South Australia and Western Australia, and "paper, scissors, rock" in Queensland, though this has been disputed.[10]

In New Zealand, the most common name in English is "paper, scissors, rock".[11] In Māori, it is known as pēpa, kutikuti, kōhatu (lit.'paper, scissors, rock').[12]

In France, the game is sometimes called Shifumi (sometimes spelled Chifoumi).[citation needed]

Etymology

[edit]

The name "rock paper scissors" is simply a translation of the Japanese words for the three gestures involved in the game,[13] though the Japanese name for the game is different.

The name Roshambo or Rochambeau has been claimed to refer to Count Rochambeau, who allegedly played the game during the American Revolutionary War. The legend that he played the game is apocryphal, as all evidence points to the game being brought to the United States later than 1910; if this name has anything to do with him it is for some other reason.[14][15] It is unclear why this name became associated with the game, with hypotheses ranging from a slight phonetic similarity with the Japanese name jan-ken-pon,[14] to the presence of a statue of Rochambeau in a neighborhood of Washington, DC.[15]

Gameplay

[edit]
Each of the three basic hand signs (from left to right: rock, paper, and scissors) beats one of the other two, and loses to the other.

The players may start by counting to three aloud, or by speaking the name of the game (e.g. "Rock! Paper! Scissors!"), raising one hand in a fist and swinging it down with each syllable onto their other hand (or in a less common variant, holding it behind their back). They then "throw" or "shoot" by extending their selected sign towards their opponent on what would have been the fourth count, often saying the word "shoot" while doing so.

Variations include a version where players throw immediately on the third count (thus throwing on the count of "Scissors!"), a version including five counts rather than four ("Rock! Paper! Scissors! Says! Shoot!"), and a version where players say "Scissors! Paper! Rock!", and a version where players shake their hands three times before "throwing".[citation needed]

History

[edit]

Origins

[edit]

The first known mention of the game was in the book Wuzazu [zh] by the Ming-dynasty writer Xie Zhaozhe [zh] (fl. c. 1600), who wrote that the game dated back to the time of the Han dynasty (206 BCE – 220 CE).[16] 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 huaquan (划拳).

Mushi-ken, the earliest Japanese sansukumi-ken game (1809). From left to right: slug (namekuji), frog (kawazu) and snake (hebi).

From China the game was brought to Japan.[17] Throughout Japanese history there are frequent references to sansukumi-ken, meaning ken (fist) games "of the three who are afraid of one another" (i.e. A beats B, B beats C, and C beats A).[17]

The earliest sansukumi-ken in Japan was apparently mushi-ken (虫拳), a version imported directly from China.[17][18] In mushi-ken the "frog" (represented by the thumb) triumphs over the "slug" (represented by the little finger), which, in turn prevails over the "snake" (represented by the index finger), which triumphs over the "frog".[17][18] (The Chinese and Japanese versions differ in the animals represented; in adopting the game, the Chinese characters for the venomous centipede (蜈蜙) were apparently confused with the characters for the slug (蛞蝓)).[18]

The most popular sansukumi-ken game in Japan[when?] was kitsune-ken (狐拳). In this game, a fox (狐), often attributed supernatural powers in Japanese folklore, defeats the village head, the village head (庄屋) defeats the hunter, and the hunter (猟師) defeats the fox. Kitsune-ken, unlike mushi-ken or rock–paper–scissors, requires gestures with both hands.[19]

Kitsune-ken was a popular Japanese rock paper scissors variant. From left to right: The hunter (ryōshi), village head (shōya) and fox (kitsune).

Today, the best-known sansukumi-ken is called jan-ken (じゃんけん),[18] which is a variation of the Chinese games introduced in the 17th century.[20] Jan-ken uses the rock, paper, and scissors signs[17] and is the direct source of the modern version of rock paper scissors.[18] Hand-games using gestures to represent the three conflicting elements of rock, paper, and scissors have been most common since the modern version of the game was created in the late 19th century, between the Edo and Meiji periods.[21]

Spread beyond East Asia

[edit]

By the early 20th century, rock paper scissors had spread beyond East Asia, especially through increased Japanese contact with the west.[22] Its English-language name is therefore taken from a translation of the names of the three Japanese hand-gestures for rock, paper and scissors;[13] elsewhere in East Asia the open-palm gesture represents "cloth" rather than "paper".[23] The shape of the scissors is also adopted from the Japanese style.[13]

A 1921 article about cricket in the Sydney Morning Herald described "stone, scissors, and paper" as a "Teutonic method of drawing lots", which the writer "came across when travelling on the Continent once".[24] Another article, from the same year, the Washington Herald described it as a method of "Chinese gambling".[25] In Britain in 1924 it was described in a letter to The Times as a hand game, possibly of Mediterranean origin, called "zhot".[26] A reader then wrote in to say that the game "zhot" referred to was evidently Jan-ken-pon, which she had often seen played throughout Japan.[27] Although at this date the game appears to have been new enough to British readers to need explaining, the appearance by 1927 of Gerard Fairlie's popular thriller novel with the title Scissors Cut Paper,[28] followed by Fairlie's Stone Blunts Scissors (1929), suggests it quickly became popular.

The game is referred to in two of Hildegard G. Frey's novels in the Campfire Girls series: The Campfire Girls Go Motoring (1916) [29] and The Campfire Girls' Larks and Pranks (1917),[30] which suggests that it was known in America at least that early. The first passage where it appears says "In order that no feelings might be involved in any way over which car we other girls traveled in, Nyoda, Solomon-like, proposed that she and Gladys play 'John Kempo' for us. (That isn't spelled right, but no matter.)" There is no explanation in any of the places where it is referenced of what the game actually is. This suggests that the author at least believed that the game was well known enough in America that her readers would understand the reference.

In 1927 La Vie au patronage : organe catholique des œuvres de jeunesse, a children's magazine in France, described it in detail,[31] referring to it as a "jeu japonais" ("Japanese game"). Its French name, "Chi-fou-mi", is based on the Old Japanese words for "one, two, three" ("hi, fu, mi").

A 1932 New York Times article on the Tokyo rush hour describes the rules of the game for the benefit of American readers, suggesting it was not at that time widely known in the U.S.[32] Likewise, the trick-taking card game "Jan-Ken-Po", first published in 1934, describes the rules of the hand-game without mentioning any American game along the lines of "rock paper scissors". The 1933 edition of the Compton's Pictured Encyclopedia described it as a common method of settling disputes between children in its article on Japan; the name was given as "John Kem Po" and the article pointedly asserted, "This is such a good way of deciding an argument that American boys and girls might like to practice it too."[33]

Strategies

[edit]
Children in Laos playing rock paper scissors
Children in Myanmar playing rock paper scissors

It is impossible to gain an advantage over an opponent that chooses their move uniformly at random. However, it is possible to gain a significant advantage over a non-random player by predicting their move, which can be done by exploiting psychological effects or by analyzing statistical patterns of their past behavior.[34][35][36] As a result, there have been programming competitions for algorithms that play rock paper scissors.[34][37][38]

During tournaments, players often prepare their sequence of three gestures prior to the tournament's commencement.[39][40] Some tournament players employ tactics to confuse or trick the other player into making an illegal move, resulting in a loss. One such tactic is to shout the name of one move before throwing another, in order to misdirect and confuse their opponent.[citation needed]

The "rock" move, in particular, is notable in that it is typically represented by a closed fist—often identical to the fist made by players during the initial countdown. If a player is attempting to beat their opponent based on quickly reading their hand gesture as the players are making their moves, it is possible to determine if the opponent is about to throw "rock" based on their lack of hand movement, as both "scissors" and "paper" require the player to reposition their hand. This can likewise be used to deceive an anticipating opponent by keeping one's fist closed until the last possible moment, leading them to believe that one is about to throw "rock".[citation needed]

Algorithms

[edit]

As a consequence of rock paper scissors programming contests, many strong algorithms have emerged.[34][37][38] For example, Iocaine Powder, which won the First International RoShamBo Programming Competition in 1999,[37] uses a heuristically designed compilation of strategies.[41] For each strategy it employs, it also has six metastrategies which defeat second-guessing, triple-guessing, as well as second-guessing the opponent, and so on. The optimal strategy or metastrategy is chosen based on past performance. The main strategies it employs are history matching, frequency analysis, and random guessing. Its strongest strategy, history matching, searches for a sequence in the past that matches the last few moves in order to predict the next move of the algorithm. In frequency analysis, the program simply identifies the most frequently played move. The random guess is a fallback method that is used to prevent a devastating loss in the event that the other strategies fail. There have since been some innovations, such as using multiple history-matching schemes that each match a different aspect of the history – for example, the opponent's moves, the program's own moves, or a combination of both.[42] There have also been other algorithms based on Markov chains.[43]

In 2012, researchers from the Ishikawa Watanabe Laboratory at the University of Tokyo created a robot hand that can play rock paper scissors with a 100% win rate against a human opponent. Using a high-speed camera the robot recognizes within one millisecond which shape the human hand is making, then produces the corresponding winning shape.[44][45]

Variations

[edit]
A print by Kikukawa Eizan that shows geisha playing kitsune-ken, a Japanese rock paper scissors variant (1820)

There exist numerous cultural and personal variations on rock paper scissors. Differences vary from simply playing the same game with different objects to expanding into more weapons and rules.

Different rules

[edit]

In Korea, where the standard version of the game is called gawi-bawi-bo, a more complex version exists by the name muk-jji-ppa.[46] After showing their hands, the player with the winning throw shouts "muk-jji-ppa!" upon which both players throw again. If they throw differently, whoever wins this second round shouts "muk-jji-ppa!" and thus the play continues until both players throw the same, at which point whoever was the last winner becomes the final winner.

In "rock paper scissors minus one", another popular variant in Korea, both players throw with both hands simultaneously. Each player chooses one hand to remove, and the winner is decided by the remaining hands in play; a tie leads to a replay.[47] This variation was featured in the second season of the Netflix series Squid Game.[48][49]

In Japan, a strip game variant of rock paper scissors is known as 野球拳 (Yakyūken). The loser of each round removes an article of clothing. The game is a minor part of porn culture in Japan and other Asian countries after the influence of TV variety shows and Soft On Demand.[citation needed]

In the Philippines, the game is called jak-en-poy (from the Japanese jankenpon). In a longer version of the game, a four-line song is sung, with hand gestures displayed at the end of each (or the final) line: "Jack-en-poy! / Hali-hali-hoy! / Sino'ng matalo, / siya'ng unggoy!" ("Jack-en-poy! / Hali-hali-hoy! / Whoever loses is the monkey!") In the former case, the person with the most wins at the end of the song, wins the game. A shorter version of the game uses the chant "Bato-bato-pick" ("Rock-rock-pick [i.e. choose]") instead.[citation needed]

A variation with more players can be played: Players stand in a circle and all throw at once. If rock, paper, and scissors are all thrown, it is a stalemate, and they rethrow. If only two throws are present, all players with the losing throw are eliminated. Play continues until only the winner remains.[50]

Different weapons

[edit]

In Indonesia, the game is called suten, suit or just sut, and the three signs are elephant (slightly raised thumb), human (outstreched index finger) and ant (outstreched pinky finger).[51] Elephant is stronger than human, human is stronger than ant, but elephant is afraid of the ant.

Using the same tripartite division, there is a full-body variation in lieu of the hand signs called "Bear, Hunter, Ninja".[52] In this iteration the participants stand back-to-back and at the count of three (or ro-sham-bo as is traditional) turn around facing each other using their arms evoking one of the totems.[53] The players' choices break down as: Hunter shoots bear; Bear eats ninja; Ninja kills hunter.[54]

Additional weapons

[edit]

Generalized rock-paper-scissors games where the players have a choice of more than three weapons have been studied.[55] Any variation of rock paper scissors is an oriented graph, where the nodes represent the symbols (weapons) choosable by the players, and an edge from A to B means that A defeats B. Each oriented graph is a potentially playable rock paper scissors game. According to theoretical calculations, the number of distinguishable (i.e. not isomorphic) oriented graphs grows with the number of weapons = 3, 4, 5, ... as follows:[56][57]

7, 42, 582, 21480, 2142288, 575016219, 415939243032, ... (sequence A001174 in the OEIS).

The French game pierre, papier, ciseaux, puits (stone, paper, scissors, well) is unbalanced; both the stone and scissors fall in the well and lose to it, while paper covers both stone and well. This means two "weapons", well and paper, can defeat two moves, while the other two weapons each defeat only one of the other three choices. The stone has no advantage to well, so optimal strategy is to play each of the other objects (paper, scissors and well) one-third of the time.[58]

"pierre, papier, ciseaux, puits";
+ means that the row player "beats", − means "is beaten" and O means tie
Opponent

Row
player
stone paper scissors well Optimal strategy for
the row player[58]
stone O +
paper + O +
scissors + O
well + + O

Variants in which the number of moves is an odd number and each move defeats exactly half of the other moves while being defeated by the other half are typically considered. Variations with up to 101 different moves have been published.[59] Adding new gestures has the effect of reducing the odds of a tie, while increasing the complexity of the game. The probability of a tie in an odd-number-of-weapons game can be calculated based on the number of weapons n as 1/n, so the probability of a tie is 1/3 in standard rock paper scissors, but 1/5 in a version that offered five moves instead of three.[60]

Rock paper scissors lizard Spock gestures

One popular five-weapon expansion is "rock paper scissors Spock lizard", invented by Sam Kass and Karen Bryla,[61] which adds "Spock" and "lizard" to the standard three choices. "Spock" is signified with the Star Trek Vulcan salute, while "lizard" is shown by forming the hand into a sock-puppet-like mouth. Spock smashes scissors and vaporizes rock; he is poisoned by lizard and disproved by paper. 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[62] and was later the subject of an episode of the American sitcom The Big Bang Theory in 2008 (as rock-paper-scissors-lizard-Spock).[63]

Rock-Paper-Scissors-Spock-Lizard;
+ means that the row player "beats", − means "is beaten" and O means tie
Opponent

Row
player
rock paper scissors Spock lizard Optimal strategy
for row player
rock O + +
paper + O +
scissors + O +
Spock + + O
lizard + + O
Oriented graph of Rock-Paper-Scissors-Fire-Water

A game-theoretic analysis showed that 4 variants of 582 possible variations using 5 different weapons have non-trivial mixed strategy equilibria.[57] The most representative game of these 4 is "rock, paper, scissors, fire, water". Rock beats scissors, paper beats rock, scissors beats paper, fire beats everything except water, and water is beaten by everything except it beats fire. The perfect game-theoretic strategy is to use rock, paper, and scissors of the time and of the time for fire and water. Nevertheless, experiments show that people underuse water and overuse rock, paper, and scissors in this game.[64]

Rock-Paper-Scissors-Fire-Water;
+ means that the row player "beats", − means "is beaten" and O means tie
Opponent

Row
player
rock paper scissors fire water Optimal strategy
for row player[57]
rock O + +
paper + O +
scissors + O +
fire + + + O
water + O

Analogues in real life

[edit]

Lizard mating strategies

[edit]

The common side-blotched lizard (Uta stansburiana) exhibits a rock paper scissors pattern in its mating strategies. Of its three throat color types of males, "orange beats blue, blue beats yellow, and yellow beats orange" in competition for females, which is similar to the rules of rock-paper-scissors.[65][66]

Bacteria

[edit]

Some bacteria also exhibit a rock paper scissors dynamic when they engage in antibiotic production. The theory for this finding was demonstrated by computer simulation and in the laboratory by Benjamin Kerr, working at Stanford University with Brendan Bohannan.[67] Additional in vitro results demonstrate rock paper scissors dynamics in additional species of bacteria.[68] Biologist Benjamin C. Kirkup Jr. demonstrated that these antibiotics, bacteriocins, were active as Escherichia coli compete with each other in the intestines of mice, and that the rock paper scissors dynamics allowed for the continued competition among strains: antibiotic-producers defeat antibiotic-sensitives; antibiotic-resisters multiply and withstand and out-compete the antibiotic-producers, letting antibiotic-sensitives multiply and out-compete others; until antibiotic-producers multiply again.[69]

Rock paper scissors is the subject of continued research in bacterial ecology and evolution. It is considered one of the basic applications of game theory and non-linear dynamics to bacteriology.[70] Models of evolution demonstrate how intragenomic competition can lead to rock paper scissors dynamics from a relatively general evolutionary model.[71] The general nature of this basic non-transitive model is widely applied in theoretical biology to explore bacterial ecology and evolution.[72][73]

Mechanical devices and geometrical constructions

[edit]

In the televised robot combat competition BattleBots, relations between "lifters, which had wedged sides and could use forklift-like prongs to flip pure wedges", "spinners, which were smooth, circular wedges with blades on their bottom side for disabling and breaking lifters", and "pure wedges, which could still flip spinners" are analogical to relations in rock paper scissors games and called "robot Darwinism".[74]

Instances of usage

[edit]

American court case

[edit]

In 2006, American federal judge Gregory Presnell from the Middle District of Florida ordered opposing sides in a lengthy court case to settle a trivial (but lengthily debated) point over the appropriate place for a deposition using the game of rock paper scissors.[75][76] The ruling in Avista Management v. Wausau Underwriters stated:

Upon consideration of the Motion – the latest in a series of Gordian knots that the parties have been unable to untangle without enlisting the assistance of the federal courts – it is ORDERED that said Motion is DENIED. Instead, the Court will fashion a new form of alternative dispute resolution, to wit: at 4:00 P.M. on Friday, June 30, 2006, counsel shall convene at a neutral site agreeable to both parties. If counsel cannot agree on a neutral site, they shall meet on the front steps of the Sam M. Gibbons U.S. Courthouse, 801 North Florida Ave., Tampa, Florida 33602. Each lawyer shall be entitled to be accompanied by one paralegal who shall act as an attendant and witness. At that time and location, counsel shall engage in one (1) game of "rock, paper, scissors". The winner of this engagement shall be entitled to select the location for the 30(b)(6) deposition to be held somewhere in Hillsborough County during the period 11–12 July 2006.[77]

Auction house selection

[edit]
Cézanne's Large Trees Under the Jas de Bouffan sold for $11,776,000 at Christie's in 2005.[78]

In 2005, when Takashi Hashiyama, CEO of Japanese television equipment manufacturer Maspro Denkoh, decided to auction off the collection of Impressionist paintings owned by his corporation, including works by Paul Cézanne, Pablo Picasso, and Vincent van Gogh, he contacted two leading auction houses, Christie's International and Sotheby's Holdings, seeking their proposals on how they would bring the collection to the market as well as how they would maximize the profits from the sale. Both firms made elaborate proposals, but neither was persuasive enough to earn Hashiyama's approval. Unwilling to split up the collection into separate auctions, Hashiyama asked the firms to decide between themselves who would hold the auction, which included Cézanne's Large Trees Under the Jas de Bouffan, estimated to be worth between $12 million to $16 million.

The houses were unable to reach a decision. Hashiyama told the two firms to play rock paper scissors to decide who would get the rights to the auction, explaining that "it probably looks strange to others, but I believe this is the best way to decide between two things which are equally good."

The auction houses had a weekend to come up with a choice of move. Christie's went to the 11-year-old twin daughters of the international director of Christie's Impressionist and Modern Art Department Nicholas Maclean, who suggested "scissors" because "Everybody expects you to choose 'rock'." Sotheby's said that they treated it as a game of chance and had no particular strategy for the game, but went with "paper".[79] Christie's won the match and sold the $20 million collection, earning millions of dollars of commission for the auction house.

FA Women's Super League match

[edit]

Prior to a 26 October 2018 match in the FA Women's Super League, the referee, upon being without a coin for the pregame coin toss, had the team captains play rock paper scissors to determine which team would kick-off. The referee was subsequently suspended for three weeks by The Football Association.[80]

Play by chimpanzees

[edit]

In Japan, researchers have taught chimpanzees to identify winning hands according to the rules of rock paper scissors.[81]

Game design

[edit]

In many games, it is common for a group of possible choices to interact in a rock paper scissors style, where each selection is strong against a particular choice, but weak against another. Such mechanics can make a game somewhat self-balancing, prevent gameplay from being overwhelmed by a single dominant strategy and single dominant type of unit.[82]

Many card-based video games in Japan use the rock paper scissors system as their core fighting system, with the winner of each round being able to carry out their designated attack. In Alex Kidd in Miracle World, the player has to win games of rock paper scissors against each boss to proceed. Others use simple variants of rock paper scissors as subgames.

Many Nintendo role-playing games prominently feature a rock paper scissors gameplay element. In Pokémon, there is a rock paper scissors element in the type effectiveness system. For example, a Grass-typed Pokémon is weak to Fire, Fire is weak to Water, and Water is weak to Grass.[83] In the 3DS remake of Mario & Luigi: Superstar Saga and Mario & Luigi: Bowser's Inside Story, the battles in the second mode use a "Power Triangle" system based on the game's three attack types: Melee, Ranged, and Flying. In the Fire Emblem series of strategy role-playing games, the Weapon Triangle and Trinity of Magic influence the hit and damage rates of weapon types based on whether they are at an advantage or a disadvantage in their respective rock paper scissors system. In the Super Smash Bros. series, the three basic actions used during battles are described in their respective rock paper scissors system: attack, defense, and grab.

The "Card-Jitsu" minigame in Club Penguin is a rock-paper-scissors game using cards that represent the three elements, Fire, Water and Snow. Fire beats snow, snow beats water, water beats fire.

Tournaments

[edit]
Two players at the 4th UK Rock Paper Scissors Championships, 2010

Various competitive rock paper scissors tournaments have been organised by different groups.

World Rock Paper Scissors Association

[edit]

Started in 2015, the WRPSA has hosted Professional Rock Paper Scissors Tournaments all around the world.[84][85][86][87][88]

World Rock Paper Scissors Society

[edit]

The World Rock Paper Scissors Society hosted Professional Rock Paper Scissors Tournaments from 2002 to 2009. These open, competitive championships were widely attended by players from around the world and attracted widespread international media attention.[89][90][91][92][93] WRPS events were noted for their large cash prizes, elaborate staging, and colorful competitors.[94] In 2004, the championships were broadcast on the U.S. television network Fox Sports Net (later known as Bally Sports), with the winner being Lee Rammage, who went on to compete in at least one subsequent championship.[95][96] The 2007 tournament was won by Andrea Farina.[97] The last tournament hosted by the World RPS Society was in Toronto, Canada, on November 14, 2009.[98]

UK championships

[edit]

Several RPS events have been organised in the United Kingdom by Wacky Nation. The 1st UK Championship took place on 13 July 2007, and were then held annually. The 2019 event was won by Ellie Mac, who went on to pick up the cash prize of £20,000 but was unable to double her earnings in 2020 due to the coronavirus outbreak.[99]

USARPS tournaments

[edit]

USA Rock Paper Scissors League is sponsored by Bud Light. Leo Bryan Pacis was the first commissioner of the USARPS.[citation needed] Cody Louis Brown was elected as the second commissioner of the USARPS in 2014.[citation needed]

In April 2006, the inaugural USARPS Championship was held in Las Vegas. Following months of regional qualifying tournaments held across the US, 257 players were flown to Las Vegas for a single-elimination tournament at the House of Blues where the winner received $50,000. The tournament was shown on the A&E Network on 12 June 2006.

The $50,000 2007 USARPS Tournament took place at the Las Vegas Mandalay Bay in May 2007.

In 2008, Sean "Wicked Fingers" Sears beat 300 other contestants and walked out of the Mandalay Bay Hotel and Casino with $50,000 after defeating Julie "Bulldog" Crossley in the finals.

The inaugural Budweiser International Rock, Paper, Scissors Federation Championship was held in Beijing, China after the close of the 2008 Summer Olympics at Club Bud. A Belfast man won the competition.[100]

National XtremeRPS Competition 2007–2008

[edit]

The XtremeRPS National Competition is a US nationwide RPS competition with Preliminary Qualifying contests that started in January 2007 and ended in May 2008, followed by regional finals in June and July 2008. The national finals were to be held in Des Moines, Iowa, in August 2008, with a chance to win up to $5,000.

Guinness Book of World Records

[edit]

The largest rock paper scissors tournament hosted 2,950 players and was achieved by Oomba, Inc. (USA) at Gen Con 2014 in Indianapolis, Indiana, United States, on 17 August 2014.[101]

World Series

[edit]

Former Celebrity Poker Showdown host and USARPS Head Referee[102] Phil Gordon has hosted an annual $500 World Series of Rock Paper Scissors event in conjunction with the World Series of Poker since 2005.[103] The winner of the WSORPS receives an entry into the WSOP Main Event. The event is an annual fundraiser for the "Cancer Research and Prevention Foundation" via Gordon's charity Bad Beat on Cancer. Poker player Annie Duke won the Second Annual World Series of Rock Paper Scissors.[104] The tournament is taped by ESPN and highlights are covered during "The Nuts" section of ESPN's annual WSOP broadcast.[105][106][107] 2009 was the fifth year of the tournament.

Jackpot En Poy of Eat Bulaga!

[edit]

Jackpot En Poy is a game segment on the Philippines' longest running noontime variety show, Eat Bulaga!. The game is based on the classic children's game rock paper scissors (Jak-en-poy in Filipino, derived from the Japanese Jan-ken-pon) where four players are paired to compete in the three-round segment. In the first round, the first pair plays against each other until one player wins three times. The next pair then plays against each other in the second round. The winners from the first two rounds then compete against each other to finally determine the ultimate winner. The winner of the game then moves on to the final round. In the final round, the player is presented with several Dabarkads, each holding different amounts of cash prize. The player will then pick three Dabarkads who they will play rock paper scissors against. The player plays against them one at a time. If the player wins against any of the Eat Bulaga! hosts, they will win the cash prize.[108][109][110]

See also

[edit]

References

[edit]
[edit]
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Rock paper scissors is a two-player 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). 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. 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 , where no single strategy guarantees victory due to the cyclic dominance structure. 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. 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. 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. 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. 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.

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: (rock, a closed fist), (paper, an open palm), and choki (scissors, two extended fingers). This nomenclature entered English through cultural exchanges with in the late 19th and early 20th centuries, as janken evolved from earlier Japanese hand games during the and Meiji periods. In the West, an alternative name "roshambo" or "rochambeau" emerged in the early , particularly among Japanese immigrants ; the first documented use of "roshambo" appears in a 1921 Washington Herald article describing the game in . The term is likely a phonetic rendering of "jan-ken-po," the Japanese , with sometimes linking it to the French general Comte de Rochambeau, though no direct historical connection exists. 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. The first documented English usages of "rock paper scissors" emerged in American publications during the and , 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. Etymologically, the name connects to a longstanding tradition of hand-sign games in , 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.

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. This name reflects the game's deep integration into Japanese culture, where it is commonly used for quick in daily life and media. 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. The game, often called jiǎndāo bù for brevity, is a staple in children's play and social interactions across the country. 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. Among European languages, the French name is pierre-feuille-ciseaux ("stone-leaf-scissors"), though in it is often pierre-papier-ciseaux ("stone-paper-scissors"), with feuille or papier both signifying paper in the cyclic rules. In Spanish-speaking regions, it is called piedra papel o tijera ("stone paper or "), a direct chanted in sequence to determine outcomes in play or disputes. 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. Across African cultures, the game appears in various hand-game forms with local names, such as mwamba karatasi mkasi in Swahili-speaking ("rock paper scissors"), used by teachers and children for fair choices, while in 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.

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. 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. 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.

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. 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. 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. 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 , assuming no strategic bias. This underpins the game's use as a neutral tool.

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. From , the game spread to , evolving into variants under the umbrella of ("three who fear each other"), a category of featuring cyclic rules. By the 17th century, during the (1603–1868), an early Japanese iteration called mushi-ken gained traction, using gestures for a slug, , 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. In feudal , particularly during Japan's , janken and its precursors integrated into everyday social practices, serving as a neutral method for 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.

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. 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. 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. 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 as a popular playground activity among children, evolving from immigrant communities on the West Coast. By the , it gained broader visibility in media, including a 1932 New York Times article describing its use in and its inclusion in the Handbook for Recreation Leaders under the name "Rochambeau," which standardized it for American recreational use. Films of the era, such as those depicting schoolyard antics, further embedded it in , 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. 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 , digital platforms have dramatically boosted accessibility, with mobile apps and 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.

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 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. Similarly, players often repeat a winning , creating exploitable streaks that skilled opponents can target by selecting the counter-gesture. Bluffing and misdirection further enhance these observational skills by introducing deliberate to manipulate an opponent's expectations. Experienced players may feign or subtle body language cues, such as a slight fist clench suggesting rock while intending , to provoke predictable reactions based on . 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. 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 (rock to , to paper, paper to rock) after a loss. This "win-stay, lose-shift" , 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. 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. Further on opponent modeling confirms that humans gain significant from simple sequential dependencies, such as prior moves, outperforming random play in 58 dyads by exploiting these patterns, though complex dependencies yield after accounting for basics.

Computational analysis

Rock-paper-scissors is a finite, symmetric, that admits a unique mixed-strategy , where each player randomizes their choice of rock, paper, or scissors with equal probability of 13\frac{1}{3}. 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. This equilibrium, first formalized by John Nash in his 1950 dissertation, exemplifies how randomization prevents exploitation in non-cooperative games with cyclic dominance. Markov chains provide a probabilistic framework for modeling and predicting opponent moves in iterated play, treating each gesture as a state in a where the probability of the next state depends only on the current one. 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. 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. 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). 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. 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. Game theory applications highlight rock-paper-scissors as a model of non-transitive preferences, where the dominance relation forms a cyclic : rock beats scissors, scissors beat paper, and paper beats rock, creating no overall superior . In graph-theoretic terms, this is a regular on three vertices, a directed cycle where each option has out-degree 1, illustrating in and evolutionary dynamics. Such structures underpin analyses of balanced multi-player games and non-hierarchical competitions.

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 , cut , and 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. Extended formats like best-of-five or best-of-three series require players to win a 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. 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. 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. 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.

Expanded gestures

One prominent expansion of the traditional rock paper scissors game introduces two additional gestures—lizard and —creating a five-gesture variant known as rock-paper-scissors-lizard-Spock. Invented by 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. The rules specify that cut paper and decapitate lizard; paper covers rock and disproves Spock; rock crushes and lizard; lizard poisons Spock and eats paper; and Spock smashes and vaporizes rock. This gained wider following a 2005 mention in of , though it achieved mainstream popularity through its depiction in the television series in 2008. Regional and cultural adaptations sometimes incorporate new gestures to reflect local themes or elements, such as the addition of "" in certain informal variants. In one such expansion, defeats rock, , and other conventional gestures by overpowering them, but it loses to , which rusts it, preserving a balanced cycle. Similarly, interacts non-transitively by eroding rock, extinguishing (if added), and rusting or , while being absorbed by or evaporated by air in broader sets. These additions aim to extend the game's thematic relevance without disrupting the core intransitive logic. Themed versions popular among children often substitute or add playful gestures drawn from imagination or media, such as "," 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 era species. 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 . 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. 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 extensions of the original model.

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. 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. Barry Sinervo's field experiments in California confirmed these dynamics, showing population cycles over generations that mirror the game's intransitive relations. Bacterial communities provide another biological parallel, as seen in engineered and natural strains of 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 from the resistant strain, and the resistant strain falls prey to the first toxin's effects, leading to oscillatory in vitro and in vivo. This non-transitive competition, first demonstrated in , promotes coexistence and by preventing dominance, with spatial structure and resource gradients influencing cycle stability. Subsequent studies have replicated these patterns in microfluidic devices, highlighting how such cycles enhance overall community productivity compared to transitive hierarchies. 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 formalized how such games maintain diversity via negative frequency dependence, akin to natural RPS equilibria. A 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 four-year-olds after extensive 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.

Mechanical and geometric models

Mechanical models of rock paper scissors encompass engineered systems designed to replicate the game's physical gestures and processes through and . 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 by researchers at the Ishikawa Group Laboratory, . This system employs high-speed to recognize an opponent's hand gesture—rock, paper, or scissors—in approximately 1 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. 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 , the game is represented as a directed graph with three vertices corresponding to rock, , and , and edges indicating dominance: rock → , , and → rock, forming a complete directed cycle without . This structure illustrates the game's zero-sum symmetry and has been analyzed for properties like equilibria in mixed strategies, where each gesture is played with equal probability (1/3) to achieve balance. Such models extend to larger , generalizing rock paper scissors to n-player variants while preserving cyclic . 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 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 of non-transitive relations. This approach highlights geometric in modeling balanced, unpredictable competitions.

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 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. 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. This unconventional approach garnered international media attention and was praised by for efficiently advancing judicial proceedings amid attorney discord. 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 and to compete in the game. emerged victorious when its executive chose , defeating Sotheby's paper, thereby securing the exclusive consignment rights; the collection ultimately sold for over $22 million at . This instance demonstrated the game's utility in resolving vendor selection disputes without bias, influencing the ordering and marketing of auction lots. Beyond isolated high-profile cases, rock-paper-scissors serves as a tool for random selection in corporate environments, particularly during the . 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. For example, in sessions, participants use the game to randomly determine speaking orders or task allocations, ensuring no favoritism and enhancing . From a psychological perspective, rock-paper-scissors promotes perceived fairness in due to its symmetric probabilities, where each has an equal 1/3 chance of winning, tying, or losing against opponents' choices. This perceived equity stems from the game's zero-sum structure, which aligns with principles of probabilistic , making it suitable for institutional applications where trust in is essential.

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. 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. Rock-paper-scissors has been integrated into 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. 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. In , rock-paper-scissors frequently appears in films and online as a symbol of spontaneous or humor, with viral examples including Johnson's 2018 recreation of a where he always chooses "rock" due to his nickname, amplifying the game's lighthearted, relatable appeal across media. The 2024 British short film "Rock, Paper, Scissors," directed by Franz Böhm, centers on the game as a plot device for a life-or-death decision in a makeshift hospital during the 2022 Russian invasion of Ukraine. Such references underscore its global ubiquity, from comedic resolutions in to humor depicting everyday dilemmas, reinforcing its role as a universal, non-verbal communicator in entertainment.

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 , , by brothers Douglas and Graham Walker, emerged as a pioneering body for promoting rock paper scissors as a competitive sport. 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. It organized annual world championships from 2002 to 2009, attracting hundreds of participants and drawing media attention to the strategic depth of the game. 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. Launched with its inaugural national championship in 2006 in , , the league partnered with Bud Light to offer significant prizes, such as $50,000 for the winner, and broadcast events on networks like to build public interest. The USARPS emphasized professional-level competition, including qualifiers and a points system, contributing to the growth of regional tournaments across the country. The World Rock Paper Scissors Association (WRPSA), founded in 2015 in , , serves as a key international hub for rules enforcement, player rankings, and event organization. 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. Regional organizations have also proliferated to localize promotion and events. For example, in the , the first national rock paper scissors championship was held in 2007 in , , followed by a second in 2008, organized by dedicated local groups to build grassroots participation and adapt rules to British contexts. Similar bodies in other regions focus on cultural integration and community tournaments while aligning with global standards set by bodies like the WRPSA.

Major tournaments

The World Series of Rock Paper Scissors, organized annually by the World Rock Paper Scissors Society in , , 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 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. In the United States, the Bud Light-sponsored Rock Paper Scissors League (USARPS) Championships ran from to at least , emphasizing professional-level play with regional qualifiers feeding into national finals at the Resort in , . The format involved best-of-three matches in a tournament, broadcast on , and offered a $50,000 grand prize to the winner, drawing hundreds of entrants annually. Notable champions included Mario Anastasov in , Jamie Langridge in 2007, and Sean Sears in . Guinness World Records recognizes several milestones in rock paper scissors competitions, including the largest tournament with 2,950 participants, achieved by Oomba, Inc. at in , , on August 17, 2014. This event used a 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 on December 24, 2021, spanning four days to mark the mall's anniversary. Media-driven events have popularized large-scale rock paper scissors play, such as the "Jackpot En Poy" segment on the Philippine 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 .

References

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