HOME

TheInfoList



OR:

Rock paper scissors (also known by other orderings of the three items, with "rock" sometimes being called "stone," or as Rochambeau, roshambo, or ro-sham-bo) is a
hand game Hand games are games played using only the hands of the players. Hand games exist in a variety of cultures internationally, and are of interest to academic studies in ethnomusicology and music education. Hand games are used to teach music liter ...
originating in
China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
, 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). "Scissors" is identical to the two-fingered
V sign The ''V sign'' is a hand gesture in which the index and middle fingers are raised and parted to make a V shape while the other fingers are clenched. It has various meanings, depending on the circumstances and how it is presented. When displa ...
(also indicating "victory" or "peace") except that it is pointed horizontally instead of being held upright in the air. A
simultaneous Simultaneity may refer to: * Relativity of simultaneity, a concept in special relativity. * Simultaneity (music), more than one complete musical texture occurring at the same time, rather than in succession * Simultaneity, a concept in Endogenei ...
,
zero-sum game Zero-sum game is a mathematical representation in game theory and economic theory of a situation which involves two sides, where the result is an advantage for one side and an equivalent loss for the other. In other words, player one's gain is e ...
, it has three possible outcomes: a draw, a win or a loss. A player who decides to play rock will beat another player who has chosen scissors ("rock crushes scissors" or "breaks scissors" or sometimes "blunts scissors"), but will lose to one who has played paper ("paper covers rock"); a play of paper will lose to a play of scissors ("scissors cuts paper"). If both players choose the same shape, the game is tied and is usually immediately replayed to break the tie. The game spread from China while developing different variants in signs over time. Rock paper scissors is often used as a fair choosing method between two people, similar to
coin flipping Coin flipping, coin tossing, or heads or tails is the practice of throwing a coin in the air and checking obverse and reverse, which side is showing when it lands, in order to choose between two alternatives, heads or tails, sometimes used to res ...
,
drawing straws Drawing straws is a selection method, or a form of sortition, that is used by a group to choose one member of the group to perform a task after none has volunteered for it. The same practice can be used also to choose one of several volunteers, shou ...
, or throwing
dice Dice (singular die or dice) are small, throwable objects with marked sides that can rest in multiple positions. They are used for generating random values, commonly as part of tabletop games, including dice games, board games, role-playing g ...
in order to settle a dispute or make an unbiased group decision. Unlike truly
random In common usage, randomness is the apparent or actual lack of pattern or predictability in events. A random sequence of events, symbols or steps often has no :wikt:order, order and does not follow an intelligible pattern or combination. Ind ...
selection methods, however, rock paper scissors can be played with a degree of skill by recognizing and exploiting non-random behavior in opponents.


Etymology

The name Rochambeau, sometimes spelled roshambo or ro-sham-bo and used mainly in the Western United States, is a reference to Count Rochambeau, who, according to a widespread legend, played the game during the
American Revolutionary War The American Revolutionary War (April 19, 1775 – September 3, 1783), also known as the Revolutionary War or American War of Independence, was a major war of the American Revolution. Widely considered as the war that secured the independence of t ...
. This legend is clearly untrue as all evidence points to the game first becoming known in the United States during the 1930s. 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'' to the presence of a statue of Rochambeau in a neighbourhood of Washington, D.C.


Gameplay

The players may count aloud to three, or speak the name of the game (e.g. "Rock! Paper! Scissors!"), either raising one hand in a fist and swinging it down with each syllable or holding it behind their back. They then "throw" or "shoot" by extending it towards their opponent. Variations include a version where players throw immediately on the third count (thus throwing on the count of "Scissors!"), or a version where they shake their hands three times before "throwing".


History


Origins

The first known mention of the game was in the book ' by the Ming-dynasty writer ( 1600), who wrote that the game dated back to the time of the
Han dynasty The Han dynasty (, ; ) was an imperial dynasty of China (202 BC – 9 AD, 25–220 AD), established by Liu Bang (Emperor Gao) and ruled by the House of Liu. The dynasty was preceded by the short-lived Qin dynasty (221–207 BC) and a warr ...
(206 BCE – 220 CE). In the book, the game was called ''shoushiling''.
Li Rihua Li Rihua (1565–1635) was a Chinese bureaucrat, artist and art critic from Jiaxing, during the late Ming Dynasty. He wrote an extensive diary, the ''Weishuixuan riji'' (Water-Tasting Gallery Diary), from 1609 to 1616, which detailed his many acquis ...
'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). Throughout Japanese history there are frequent references to ''
sansukumi-ken Sansukumi-ken (三すくみ拳) is a category of East Asian hand games played by using three hand gestures. Ken games went into a period of decline in Japan after World War II. One of the few surviving sansukumi-ken games is jan-ken, which was broug ...
'', 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). This type of game originated in China before being imported to Japan and subsequently also becoming popular among the Japanese. The earliest Japanese ''sansukumi-ken'' game was known as ''mushi-ken'' (虫拳), which was imported directly from China. 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". Although this game was imported from China the Japanese version differs in the animals represented. In adopting the game, the original
Chinese characters Chinese characters () are logograms developed for the writing of Chinese. In addition, they have been adapted to write other East Asian languages, and remain a key component of the Japanese writing system where they are known as ''kanji' ...
for the poisonous centipede (蜈蜙) were apparently confused with the characters for the slug (蛞蝓). The most popular ''sansukumi-ken'' game in Japan was ''kitsune-ken'' ( 狐拳). In the game, a supernatural fox called a
kitsune In Japanese folklore, , are foxes that possess paranormal abilities that increase as they get older and wiser. According to ''yōkai'' folklore, all foxes have the ability to shapeshift into human form. While some folktales speak of employing t ...
(狐) 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, is played by making gestures with both hands. Today, the best-known ''sansukumi-ken'' is called , which is a variation of the Chinese games introduced in the 17th century. ''Jan-ken'' uses the rock, paper, and scissors signs and is the game that the modern version of rock paper scissors derives from directly. 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.


Spread beyond East Asia

By the early 20th century, rock paper scissors had spread beyond East Asia, especially through increased Japanese contact with the west. Its English-language name is therefore taken from a translation of the names of the three Japanese hand-gestures for rock, paper and scissors: elsewhere in East Asia the open-palm gesture represents "cloth" rather than "paper". The shape of the scissors is also adopted from the Japanese style. A 1921 article about
cricket Cricket is a bat-and-ball game played between two teams of eleven players on a field at the centre of which is a pitch with a wicket at each end, each comprising two bails balanced on three stumps. The batting side scores runs by striki ...
in the ''
Sydney Morning Herald ''The Sydney Morning Herald'' (''SMH'') is a daily compact newspaper published in Sydney, New South Wales, Australia, and owned by Nine. Founded in 1831 as the ''Sydney Herald'', the ''Herald'' is the oldest continuously published newspaper i ...
'' described "stone, scissors, and paper" as a "Teutonic method of drawing lots", which the writer "came across when travelling on the Continent once". Another article, from the same year, in the ''
Washington Herald ''The Washington Herald'' was an American daily newspaper in Washington, D.C., from October 8, 1906, to January 31, 1939. History The paper was founded in 1906 by Scott C. Bone, who had been managing editor of ''The Washington Post'' from 1888 ...
'' described it as a method of "Chinese gambling". In Britain in 1924 it was described in a letter to ''The Times'' as a hand game, possibly of Mediterranean origin, called "zhot". 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. Although at this date the game appears to have been new enough to British readers to need explaining, the appearance by 1927 of a popular thriller with the title ''Scissors Cut Paper'', followed by ''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) and ''The Campfire Girls Larks and Pranks'' (1917), 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's 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'', a children's magazine in France, described it in detail, referring to it as a "jeu japonais" ("Japanese game"). Its French name, "Chi-fou-mi", is based on the
Old Japanese is the oldest attested stage of the Japanese language, recorded in documents from the Nara period (8th century). It became Early Middle Japanese in the succeeding Heian period, but the precise delimitation of the stages is controversial. Old Jap ...
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. Likewise, the
trick-taking card game A trick-taking game is a card game, card or tile-based game in which play of a ''Hand (card games), hand'' centers on a series of finite rounds or units of play, called ''tricks'', which are each evaluated to determine a winner or ''taker'' of th ...
“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."


Strategies

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. As a result, there have been programming competitions for
algorithm In mathematics and computer science, an algorithm () is a finite sequence of rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algorithms are used as specificat ...
s that play rock paper scissors. During tournaments, players often prepare their sequence of three gestures prior to the tournament's commencement.Steve Vockrodt
"Student rivals throw down at rock, paper, scissors tournament"
''
Lawrence Journal-World The ''Lawrence Journal-World'' is a daily newspaper published in Lawrence, Kansas, United States, by Ogden Newspapers. History Though the ''Journal-World'' title came into existence in 1911, the paper dates itself to 1858, according to the ...
'', 8 April 2007. Retrieved 13 April 2007.
Michael Y. Park
"Rock, Paper, Scissors, the Sport"
, ''
Fox News The Fox News Channel, abbreviated FNC, commonly known as Fox News, and stylized in all caps, is an American multinational conservative cable news television channel based in New York City. It is owned by Fox News Media, which itself is owne ...
'', 20 March 2006. Retrieved 13 April 2007.
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. 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 you are about to throw "rock".


Algorithms

As a consequence of rock paper scissors programming contests, many strong algorithms have emerged. For example, Iocaine Powder, which won the First International RoShamBo Programming Competition in 1999, uses a heuristically designed compilation of strategies. 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. There have also been other algorithms based on
Markov chain A Markov chain or Markov process is a stochastic model describing a sequence of possible events in which the probability of each event depends only on the state attained in the previous event. Informally, this may be thought of as, "What happe ...
s. In 2012, researchers from the Ishikawa Watanabe Laboratory at the
University of Tokyo , abbreviated as or UTokyo, is a public research university located in Bunkyō, Tokyo, Japan. Established in 1877, the university was the first Imperial University and is currently a Top Type university of the Top Global University Project by ...
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 A millisecond (from '' milli-'' and second; symbol: ms) is a unit of time in the International System of Units (SI) equal to one thousandth (0.001 or 10−3 or 1/1000) of a second and to 1000 microseconds. A unit of 10 milliseconds may be called ...
which shape the human hand is making, then produces the corresponding winning shape.


Variations

Players have developed numerous cultural and personal variations on the game, from simply playing the same game with different objects, to expanding into more weapons and rules, to giving their own name to the game in their national language.


Adapted rules

In Korea, where the standard version of the game is called ''gawi-bawi-bo'', a two-player upgraded version exists by the name '' muk-jji-ppa''. After showing their hands, the player with the winning throw shouts "''muk-jji-ppa!''" upon which both players throw again. If they throw differently (for example, rock and paper, or paper and scissors), whoever wins this second round shouts "''muk-jji-ppa!''" and thus the play continues until both players throw the same item (for example, rock and rock), at which point whoever was the last winner becomes the actual winner. In another popular two-handed variant, one player will shout "minus one" after the initial play. Each player removes one hand, and the winner is decided by the remaining hands in play. In Japan, a strip game variant of rock paper scissors is known as 野球拳 ('' Yakyuken''). 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. In the
Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...
, the game is called ''jak-en-poy'' (from the Japanese ''jan-ken-pon''). 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 .e. choose) instead. A multiple player variation 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.


Different weapons

In the Malaysian version of the game, "scissors" is replaced by "bird," represented with the finger tips of five fingers brought together to form a beak. The open palm represents "water". Bird beats water (by drinking it); stone beats bird (by hitting it); and stone loses to water (because it sinks in it). Singapore also has a related hand-game called "''ji gu pa''", where "''ji''" refers to the bird gesture, "''gu''" refers to the stone gesture, and "''pa''" refers to the water gesture. The game is played by two players using both hands. At the same time, they both say, "''ji gu pa!''" At "''pa!''" they both show two open-palmed hands. One player then changes his hand gestures while calling his new combination out (e.g., "''pa gu!''"). At the same time, the other player changes his hand gestures as well. If one of his hand gestures is the same as the other one, that hand is "out" and he puts it behind his back; he is no longer able to play that hand for the rest of the round. The players take turns in this fashion, until one player loses by having both hands sent "out". "''Ji gu pa''" is most likely a transcription of the Japanese names for the different hand gestures in the original jan-ken game, "''choki''" (scissors), "''guu''" (rock) and "''paa''" (paper). 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). 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". 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. The players' choices break down as: Hunter shoots bear; Bear eats ninja; Ninja kills hunter. The game was popularized with a
FedEx FedEx Corporation, formerly Federal Express Corporation and later FDX Corporation, is an American multinational conglomerate holding company focused on transportation, e-commerce and business services based in Memphis, Tennessee. The name "Fe ...
commercial where warehouse employees had too much free time on their hands.


Additional weapons

Generalized rock-paper-scissors games where the players have a choice of more than three weapons have been studied. Any variation of rock paper scissors is an
oriented graph In graph theory, an orientation of an undirected graph is an assignment of a direction to each edge, turning the initial graph into a directed graph. Oriented graphs A directed graph is called an oriented graph if none of its pairs of vertices is ...
, where the
nodes In general, a node is a localized swelling (a "knot") or a point of intersection (a Vertex (graph theory), vertex). Node may refer to: In mathematics *Vertex (graph theory), a vertex in a mathematical graph *Vertex (geometry), a point where two ...
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 In mathematics, an isomorphism is a structure-preserving mapping between two structures of the same type that can be reversed by an inverse mapping. Two mathematical structures are isomorphic if an isomorphism exists between them. The word is ...
) oriented graphs grows with the number of weapons = 3, 4, 5, ... as follows: : 7; 42; 582; 21,480; 2,142,288; 575,016,219; 415,939,243,032; … . The French game "pierre, papier, ciseaux, puits" (stone, paper, scissors,
well A well is an excavation or structure created in the ground by digging, driving, or drilling to access liquid resources, usually water. The oldest and most common kind of well is a water well, to access groundwater in underground aquifers. The ...
) 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 rock 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. 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. 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. One popular five-weapon expansion is "", invented by Sam Kass and Karen Bryla, which adds "
Spock Spock is a Character (arts), fictional character in the ''Star Trek'' media franchise. He first appeared in the Star Trek: The Original Series, original ''Star Trek'' series serving aboard the starship USS Enterprise (NCC-1701), USS ''Enterprise ...
" and "
lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...
" to the standard three choices. "Spock" is signified with the ''Star Trek''
Vulcan salute The Vulcan salute ("🖖") is a hand gesture popularized by the 1960s television series ''Star Trek''. It consists of a raised hand with the palm forward and the thumb extended, while the fingers are parted between the middle and ring fin ...
, 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 ''The Times'' is a British daily national newspaper based in London. It began in 1785 under the title ''The Daily Universal Register'', adopting its current name on 1 January 1788. ''The Times'' and its sister paper ''The Sunday Times'' (fou ...
'' of London and was later the subject of an
episode An episode is a narrative unit within a larger dramatic work or documentary production, such as a series intended for radio, television or streaming consumption. The noun ''episode'' is derived from the Greek term ''epeisodion'' (), meaning t ...
of the American
sitcom A sitcom, a portmanteau of situation comedy, or situational comedy, is a genre of comedy centered on a fixed set of characters who mostly carry over from episode to episode. Sitcoms can be contrasted with sketch comedy, where a troupe may use ne ...
''
The Big Bang Theory ''The Big Bang Theory'' is an American television sitcom created by Chuck Lorre and Bill Prady, both of whom served as executive producers on the series, along with Steven Molaro, all of whom also served as head writers. It premiered on CBS ...
'' in 2008 (as rock-paper-scissors-lizard-Spock). A game-theoretic analysis showed that 4 variants of 582 possible variations using 5 different weapons have non-trivial mixed strategy equilibria. 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 \frac of the time and \frac of the time for fire and water. Nevertheless, experiments show that people underuse water and overuse rock, paper, and scissors in this game.


Analogues in real life


Lizard mating strategies

The
common side-blotched lizard The common side-blotched lizard (''Uta stansburiana'') is a species of side-blotched lizard in the family Phrynosomatidae. The species is native to dry regions of the western United States and northern Mexico. It is notable for having a unique fo ...
(''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.


Bacteria

Some bacteria also exhibit a rock paper scissors dynamic when they engage in
antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...
production. The theory for this finding was demonstrated by computer simulation and in the laboratory by Benjamin Kerr, working at
Stanford University Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is consider ...
with Brendan Bohannan. Additional ''in vitro'' results demonstrate rock paper scissors dynamics in additional species of bacteria. Biologist Benjamin C. Kirkup Jr. demonstrated that these antibiotics,
bacteriocin Bacteriocins are proteinaceous or peptidic toxins produced by bacteria to inhibit the growth of similar or closely related bacterial strain(s). They are similar to yeast and paramecium killing factors, and are structurally, functionally, and ec ...
s, 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. 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 Game theory is the study of mathematical models of strategic interactions among rational agents. Myerson, Roger B. (1991). ''Game Theory: Analysis of Conflict,'' Harvard University Press, p.&nbs1 Chapter-preview links, ppvii–xi It has appli ...
and non-linear dynamics to bacteriology. Models of evolution demonstrate how intragenomic competition can lead to rock paper scissors dynamics from a relatively general evolutionary model. The general nature of this basic non-transitive model is widely applied in theoretical biology to explore bacterial ecology and evolution.


Mechanical devices and geometrical constructions

In the televised
robot combat Robot combat is a mode of robot competition in which custom-built machines fight using various methods to incapacitate each other. The machines have generally been remote-controlled vehicles rather than autonomous robots. Robot combat compet ...
competition ''
BattleBots ''BattleBots'' (logo: Bꓭ)In season 10, the 2020-2021 TV season, the show introduced the "Bꓭ" logo is an American robot combat television series. The show was an adaptation of the British show '' Robot Wars'', in which competitors design and o ...
'', 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".


Instances of usage


American court case

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. The ruling in ''Avista Management v. Wausau Underwriters'' stated:


Auction house selection

In 2005, when Takashi Hashiyama, CEO of Japanese television equipment manufacturer
Maspro Denkoh Maspro Denkoh is a Japanese electronics manufacturer. In 2005, the firm chose the auctioneer of their $20 million art collection through a game of rock, paper, scissors. Christie's won.. References External linksMaspro DenkohImpressionist Impressionism was a 19th-century art movement characterized by relatively small, thin, yet visible brush strokes, open composition, emphasis on accurate depiction of light in its changing qualities (often accentuating the effects of the passage ...
paintings owned by his corporation, including works by
Paul Cézanne Paul Cézanne ( , , ; ; 19 January 1839 – 22 October 1906) was a French artist and Post-Impressionism, Post-Impressionist painter whose work laid the foundations of the transition from the 19th-century conception of artistic endeavour to a ...
,
Pablo Picasso Pablo Ruiz Picasso (25 October 1881 – 8 April 1973) was a Spanish painter, sculptor, printmaker, ceramicist and Scenic design, theatre designer who spent most of his adult life in France. One of the most influential artists of the 20th ce ...
, and
Vincent van Gogh Vincent Willem van Gogh (; 30 March 185329 July 1890) was a Dutch Post-Impressionism, Post-Impressionist painter who posthumously became one of the most famous and influential figures in Western art history. In a decade, he created about 2 ...
, he contacted two leading auction houses,
Christie's Christie's is a British auction house founded in 1766 by James Christie (auctioneer), James Christie. Its main premises are on King Street, St James's in London, at Rockefeller Center in New York City and at Alexandra House in Hong Kong. It is ...
International and
Sotheby's Sotheby's () is a British-founded American multinational corporation with headquarters in New York City. It is one of the world's largest brokers of fine and decorative art, jewellery, and collectibles. It has 80 locations in 40 countries, and ...
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'', worth between $12 million and $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 A game of chance is in contrast with a game of skill. It is a game whose outcome is strongly influenced by some randomizing device. Common devices used include dice, spinning tops, playing cards, roulette wheels, or numbered balls drawn from a ...
and had no particular strategy for the game, but went with "paper". 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

Prior to a 26 October 2018 match in the
FA Women's Super League The Women's Super League (WSL), currently known as the Barclays Women's Super League (BWSL) for sponsorship reasons, is the highest league of women's football in England. Established in 2010, it is run by the Football Association and features t ...
, the referee, upon being without a coin for the pregame
coin toss A coin is a small, flat (usually depending on the country or value), round piece of metal or plastic used primarily as a medium of exchange or legal tender. They are standardized in weight, and produced in large quantities at a mint in order to ...
, 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 The Football Association (also known as The FA) is the Sports governing body, governing body of association football in England and the Crown Dependencies of Jersey, Bailiwick of Guernsey, Guernsey and the Isle of Man. Formed in 1863, it is the ...
.


Play by chimpanzees

In Japan, researchers have taught
chimpanzee The chimpanzee (''Pan troglodytes''), also known as simply the chimp, is a species of great ape native to the forest and savannah of tropical Africa. It has four confirmed subspecies and a fifth proposed subspecies. When its close relative th ...
s to identify winning hands according to the rules of rock paper scissors.


Game design

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 In game theory, strategic dominance (commonly called simply dominance) occurs when one strategy is better than another strategy for one player, no matter how that player's opponents may play. Many simple games can be solved using dominance. The ...
and single dominant type of unit. 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 is a platform game for the Master System. It was released in Japan on November 1, 1986, followed by the United States in December 1986, with Europe in September 1987, plus South Korea in October 1988, and Brazil in 1989. It was later built into ...
'', 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 is a Japanese Multinational corporation, multinational video game company headquartered in Kyoto, Japan. It develops video games and video game consoles. Nintendo was founded in 1889 as by craftsman Fusajiro Yamauchi and originally produce ...
role-playing games prominently feature a rock paper scissors gameplay element. In ''
Pokémon (an abbreviation for in Japan) is a Japanese media franchise managed by The Pokémon Company, founded by Nintendo, Game Freak, and Creatures (company), Creatures, the owners of the trademark and copyright of the franchise. In terms of ...
'', 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. 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 is a fantasy tactical role-playing game franchise developed by Intelligent Systems and published by Nintendo. First produced and published for the Famicom in 1990, the series currently consists of sixteen core entries and five spinoffs. Game ...
'' 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.


Tournaments

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


World Rock Paper Scissors Association

Started in 2015 the WRPSA has hosted Professional Rock Paper Scissors Tournaments all around the World.


World Rock Paper Scissors Society

Hosted Professional Rock Paper Scissors Tournaments from 2002–2009. These open, competitive championships have been widely attended by players from around the world and have attracted widespread international media attention. WRPS events are noted for their large cash prizes, elaborate staging, and colorful competitors. In 2004, the championships were broadcast on the U.S. television network
Fox Sports Net Fox Sports Networks (FSN), formerly known as Fox Sports Net, was the collective name for a group of regional sports channels in the United States. Formed in 1996 by News Corporation, the networks were acquired by The Walt Disney Company on Mar ...
(later known as
Bally Sports The Bally Sports Regional Networks are a group of regional sports networks in the United States owned by Diamond Sports Group, a joint-venture company of the Sinclair Broadcast Group and Entertainment Studios. The naming rights to the network we ...
), with the winner being Lee Rammage, who went on to compete in at least one subsequent championship. The 2007 tournament was won by Andrea Farina. The last tournament hosted by the World RPS Society was in Toronto, Canada, on November 14, 2009.


UK championships

Several RPS events have been organised in the United Kingdom by
Wacky Nation Eccentricity (also called quirkiness) is an unusual or odd behavior on the part of an individual. This behavior would typically be perceived as unusual or unnecessary, without being demonstrably maladaptive. Eccentricity is contrasted with norm ...
. 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.


USARPS tournaments

USA Rock Paper Scissors League The United States of America Rock Paper Scissors League was a national competition league for the hand game rock paper scissors. The first national champion was crowned on April 9, 2006, at the USARPS League Championship, which was held at the Ma ...
is sponsored by Bud Light. Leo Bryan Pacis was the first commissioner of the USARPS. Cody Louis Brown was elected as the second commissioner of the USARPS in 2014. In April 2006, the inaugural USARPS Championship was held in
Las Vegas Las Vegas (; Spanish for "The Meadows"), often known simply as Vegas, is the 25th-most populous city in the United States, the most populous city in the state of Nevada, and the county seat of Clark County. The city anchors the 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 House of Blues is an American chain of live music concert halls and restaurants. It was founded by Isaac Tigrett, the co-founder of Hard Rock Cafe, and Dan Aykroyd, co-star of the 1980 film ''The Blues Brothers''. The first location opened at ...
where the winner received $50,000. The tournament was shown on the
A&E Network A&E is an American basic cable network, the flagship television property of A&E Networks. The network was originally founded in 1984 as the Arts & Entertainment Network, initially focusing on fine arts, documentaries, television drama, dramas, and ...
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 } Beijing ( ; ; ), alternatively romanized as Peking ( ), is the capital of the People's Republic of China. It is the center of power and development of the country. Beijing is the world's most populous national capital city, with over 21 ...
, China after the close of the 2008 Summer Olympics at Club Bud. A Belfast man won the competition.


National XtremeRPS Competition 2007–2008

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 Des Moines () is the capital and the most populous city in the U.S. state of Iowa. It is also the county seat of Polk County. A small part of the city extends into Warren County. It was incorporated on September 22, 1851, as Fort Des Moines, ...
, in August 2008, with a chance to win up to $5,000.


''Guinness Book of World Records''

The largest rock paper scissors tournament hosted 2,950 players and was achieved by Oomba, Inc. (USA) at
Gen Con Gen Con is the largest tabletop game convention in North America by both attendance and number of events. It features traditional pen-and-paper, board, and card games, including role-playing games, miniatures wargames, live action role-playing ...
2014 in
Indianapolis, Indiana Indianapolis (), colloquially known as Indy, is the state capital and most populous city of the U.S. state of Indiana and the seat of Marion County. According to the U.S. Census Bureau, the consolidated population of Indianapolis and Mari ...
, United States, on 17 August 2014.


World Series

Former
Celebrity Poker Showdown ''Celebrity Poker Showdown'' is an American celebrity game show that aired on the cable network Bravo (US TV channel), Bravo. It was a limited-run series in which celebrities played poker, with eight Poker tournament, tournaments during its five-s ...
host and USARPS Head Referee Phil Gordon has hosted an annual $500 World Series of Rock Paper Scissors event in conjunction with the
World Series of Poker The World Series of Poker (WSOP) is a series of poker tournaments held annually in Paradise, Nevada and, since 2004, sponsored by Caesars Entertainment. It dates its origins to 1970, when Benny Binion invited seven of the best-known poker pla ...
since 2005. The winner of the WSORPS receives an entry into the
WSOP Main Event The World Series of Poker (WSOP) is a series of poker tournaments held annually in Paradise, Nevada and, since 2004, sponsored by Caesars Entertainment. It dates its origins to 1970, when Benny Binion invited seven of the best-known poker play ...
. 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 Anne LaBarr Duke (née Lederer; born September 13, 1965) is an American former professional poker player and author in cognitive-behavioral decision science and decision education. She holds a World Series of Poker (WSOP) gold bracelet from 2004 ...
won the Second Annual World Series of Rock Paper Scissors. The tournament is taped by ESPN and highlights are covered during "The Nuts" section of ESPN's annual WSOP broadcast. 2009 was the fifth year of the tournament.


''Jackpot En Poy'' of ''Eat Bulaga!''

Jackpot En Poy is a game segment on the Philippines' longest running noontime variety show, ''
Eat Bulaga! ''Eat Bulaga!'' (), formerly ''Eat... Bulaga!'', is a noontime Philippine television variety show broadcast by GMA Network. Produced by TAPE Inc., it is the longest running variety show in the Philippines with over 13,000 episodes. Originally ...
''. The game is based on the classic children's game rock paper scissors 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 he or she 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, he or she will win the cash prize.


See also

*
Chopsticks (hand game) Chopsticks is a hand game for two or more players, in which players extend a number of fingers from each hand and transfer those scores by taking turns to tap one hand against another. Chopsticks is an example of a combinatorial game, and is s ...
*
Matching pennies Matching pennies is the name for a simple game used in game theory. It is played between two players, Even and Odd. Each player has a penny and must secretly turn the penny to heads or tails. The players then reveal their choices simultaneously ...
, the binary equivalent *
Morra (game) Morra is a hand game that dates back thousands of years to ancient Roman and Greek times. Each player simultaneously reveals their hand, extending any number of fingers, and calls out a number. Any player who successfully guesses the total number ...
, another hand game for deciding trivial matters *
Intransitive dice A set of dice is intransitive (or nontransitive) if it contains three dice, ''A'', ''B'', and ''C'', with the property that ''A'' rolls higher than ''B'' more than half the time, and ''B'' rolls higher than ''C'' more than half the time, but it is ...
* Rock paper scissors and human social cyclic behavior * Simultaneous action selection *
Mixed strategy In game theory, a player's strategy is any of the options which they choose in a setting where the outcome depends ''not only'' on their own actions ''but'' on the actions of others. The discipline mainly concerns the action of a player in a game ...


References

Notes Bibliography * * Culin, Stewart (1895) ''Korean Games, With Notes on the Corresponding Games at China and Japan''. (evidence of nonexistence of rock paper scissors in the West) * Gomme, Alice Bertha (1894, 1898) ''The traditional games of England, Scotland, and Ireland'', 2 vols. (more evidence of nonexistence of rock paper scissors in the West) * Opie, Iona & Opie, Peter (1969) ''Children's Games in Street and Playground'' Oxford University Press, London. (Details some variants on rock paper scissors such as 'Man, Earwig, Elephant' in Indonesia, and presents evidence for the existence of 'finger throwing games' in Egypt as early as 2000 B.C.) * * * * * * Baldwin, Wyatt (2017
The Official Rock Paper Scissors Handbook
''The Official Strategy Guide of th
World Rock Paper Scissors Association
' * Walker, Douglas & Walker, Graham (2004) ''The Official Rock Paper Scissors Strategy Guide''. Fireside. (strategy, tips and culture from the World Rock Paper Scissors Society).


External links

* *
A biological example of rock paper scissors: Interview with biologist Barry Sinervo on the 7th Avenue Project Radio Show

The World Rock Paper Scissors Association

Rock Paper Scissors Programming Competition

Rock Paper Scissors online remote edition
* {{Authority control Children's games Games of chance Hand games Japanese games Sampling (statistics) Game theory game classes