View source for Rock paper scissors

{{Short description|Hand game for two players or more}}
{{Other uses|Rock paper scissors (disambiguation)}}
{{redirect|Ro Sham Bo|the album by The Grays|Ro Sham Bo (album){{!}}''Ro Sham Bo'' (album)}}
{{Infobox game
| italic title = no
|name=| image = Rock-paper-scissors.svg
| image_caption = 
| years =
| genre = [[Hand game]]
| players = 2 (or more)
| setup_time = None
| playing_time = seconds
| random_chance = High
}}

'''Rock paper scissors''' (also known by several other names and word orders, see [[#Names|§ Names]]) is an [[Intransitive game|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 "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.

A [[simultaneous game|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"<ref>{{cite book |last1=Fisher |first1=Len |title=Rock, Paper, Scissors: Game Theory in Everyday Life |date=2008 |publisher=Basic Books |isbn=9780786726936 |page=[https://archive.org/details/isbn_9780465009381/page/92 92] |url=https://archive.org/details/isbn_9780465009381 |url-access=registration |language=en}}</ref>), 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 [[randomness|random]] selection methods, however, rock paper scissors can be played with some degree of skill by recognizing and exploiting non-random behavior in opponents.<ref>{{cite book|last=Fisher|first=Len|title=Rock, paper, scissors: game theory in everyday life|url=https://archive.org/details/rockpaperscissor00fish_354|url-access=limited|year=2008|publisher=Basic Books|isbn=9780786726936|page=[https://archive.org/details/rockpaperscissor00fish_354/page/n106 94]}}</ref><ref>{{cite news|url=https://www.bbc.com/news/science-environment-27228416|title=How to win at rock-paper-scissors|work=BBC News|date=2 May 2014|access-date=2 May 2015|archive-date=6 May 2015|archive-url=https://web.archive.org/web/20150506084058/http://www.bbc.com/news/science-environment-27228416|url-status=live}}</ref>

==Etymology==
The name "rock paper scissors" is simply a translation of the Japanese words for the three gestures involved in the game,<ref name="長田須磨・須山名保子共編 1977.4">{{Cite book
 |last=長田須磨・須山名保子共編 
 |title=『奄美方言分類辞典』上巻 
 |url=https://www.amazon.co.jp/dp/B000J8V5WU 
 |date=April 1977 
 |publisher=Kasama shoin 
 |location=Tokyo 
 |asin=B000J8V5WU 
 |asin-tld=co.jp 
 |archive-url=https://web.archive.org/web/20150714053837/http://www.amazon.co.jp/gp/product/B000J8V5WU?%2AVersion%2A=1&%2Aentries%2A=0 
 |archive-date=2015-07-14 
 |url-status=live 
 |access-date=2015-07-14 
}}</ref> though the Japanese name for the game is different.

The name Roshambo or Rochambeau has been claimed to refer to [[Jean-Baptiste Donatien de Vimeur, comte de Rochambeau|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.<ref name="mentalfloss">{{cite web |url=https://www.mentalfloss.com/article/80201/why-do-people-call-rock-paper-scissors-roshambo |title=Why Do People Call Rock-Paper-Scissors "Roshambo?" |last=Ferro |first=Shaunacy |date=May 18, 2016 |website=[[Mental Floss]] |access-date=June 9, 2021 |archive-date=June 9, 2021 |archive-url=https://web.archive.org/web/20210609121842/https://www.mentalfloss.com/article/80201/why-do-people-call-rock-paper-scissors-roshambo |url-status=live }}</ref><ref name="teachinghistory">{{cite web |url=https://teachinghistory.org/history-content/ask-a-historian/23932 |title=Rock Paper Scissors |author=<!--Not stated--> |website=teachinghistory.org |publisher=Roy Rosenzweig Center for History and New Media at George Mason University |access-date=June 9, 2021 |archive-date=June 9, 2021 |archive-url=https://web.archive.org/web/20210609121843/https://teachinghistory.org/history-content/ask-a-historian/23932 |url-status=live }}</ref> 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,''<ref name="mentalfloss"/> to the presence of a statue of Rochambeau in a neighborhood of Washington, DC.<ref name="teachinghistory"/>

==Names==
The modern game is known by several other names such as '''Rochambeau''', '''Roshambo''', '''Ro-sham-bo''', '''Bato Bato Pik''', and '''Jak-en-poy'''.<ref name=rpscamps>{{cite web|url=http://www.rpschamps.com/templates/j15_rps/images/propaganda/faq/game-basics/|title=Game Basics|access-date=2009-12-05|archive-url=https://web.archive.org/web/20120114215304/http://www.rpschamps.com/templates/j15_rps/images/propaganda/faq/game-basics/|archive-date=2012-01-14|url-status=usurped}}</ref><ref>{{cite news |url=https://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2003/03/16/BA251812.DTL |title=Ready, set ... Roshambo! Contestants vie for $1,000 purse in Rock, Scissors, Paper contest |access-date=2007-11-20 |work=[[San Francisco Chronicle]] |date=2003-03-19 |first=Kelly |last=St. John |archive-date=2007-12-13 |archive-url=https://web.archive.org/web/20071213095322/http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2003/03/16/BA251812.DTL |url-status=live }}</ref><ref>{{cite web|last=Wells|first=Steven|title=It's not your dad's ick-ack-ock|url=https://www.theguardian.com/sport/2006/nov/24/1|work=[[The Guardian]]|access-date=2013-08-13|date=2006-11-24}}</ref> 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".<ref>{{cite web |title=The Origins and Evolution of Rock Paper Scissors: A History of the Game |url=https://wrpsa.com/the-origins-and-evolution-of-rock-paper-scissors-a-history-of-the-game/ |website=wrpsa.com |date=17 May 2023 |access-date=16 November 2023 |archive-date=16 November 2023 |archive-url=https://web.archive.org/web/20231116100214/https://wrpsa.com/the-origins-and-evolution-of-rock-paper-scissors-a-history-of-the-game/ |url-status=live }}</ref><ref>{{cite news |last1=Tomkins |first1=Steve |title=Scissors, paper, stone - a strategic game |url=http://news.bbc.co.uk/1/hi/magazine/4521589.stm |website=news.bbc.co.uk/ |date=6 May 2005 |publisher=BBC |access-date=16 November 2023 |archive-date=18 April 2016 |archive-url=https://web.archive.org/web/20160418122010/http://news.bbc.co.uk/1/hi/magazine/4521589.stm |url-status=live }}</ref> 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!").<ref>{{cite web |title=How to Play Rock, Paper, Scissors: A Simple Guide |url=https://www.wikihow.com/Video/Play-Rock,-Paper,-Scissors |website=www.wikihow.com |access-date=16 November 2023 |archive-date=16 November 2023 |archive-url=https://web.archive.org/web/20231116100212/https://www.wikihow.com/Video/Play-Rock,-Paper,-Scissors |url-status=live }}</ref>

In Australia, the most common name is "scissors, paper, rock" (the reverse of the American format).<ref>{{cite web | url=https://www.mamalisa.com/?t=es&p=6533 | title=Scissors, Paper, Rock - Australia | access-date=2023-06-08 | archive-date=2023-08-01 | archive-url=https://web.archive.org/web/20230801160758/https://www.mamalisa.com/?t=es&p=6533 | url-status=live }}</ref> There have been claims that there are regional variations of the name in Australia; the video claimed that it was referred to as "scissors, paper, rock" in [[New South Wales]], "rock, paper, scissors" in [[Victoria (state)|Victoria]], [[South Australia]] and [[Western Australia]] and "paper, scissors, rock" in [[Queensland]], though this has been disputed.<ref>{{Cite news |last=Hicks |first=Stacey |date=2022-10-24 |title=Aussies debate the correct way to play 'Scissors, Paper, Rock' |work=[[News Corp Australia#Websites|Kidspot]] |url=https://www.kidspot.com.au/news/aussies-debate-the-correct-way-to-play-scissors-paper-rock/news-story/e34273406f9d44687d964f478693d807}}</ref>

In New Zealand, the most common name in English is "paper, scissors, rock".<ref>{{cite web | url=https://www.rnz.co.nz/news/national/467118/rock-paper-scissors-winner-fast-fingered-champ-takes-home-1000-prize#:~:text=%22In%20NZ%2C%20you%20usually%20say,scissors%20last%2C%20you%20throw%20scissors. | title=Rock, paper, scissors, winner! Fast-fingered champ takes home $1000 prize | website=[[Radio New Zealand]] | date=14 May 2022 | access-date=8 June 2023 | archive-date=1 August 2023 | archive-url=https://web.archive.org/web/20230801160638/https://www.rnz.co.nz/news/national/467118/rock-paper-scissors-winner-fast-fingered-champ-takes-home-1000-prize#:~:text=%22In%20NZ%2C%20you%20usually%20say,scissors%20last%2C%20you%20throw%20scissors. | url-status=live }}</ref> In [[Māori language|Māori]], it is known as {{lang|mi|pēpa, kutikuti, kōhatu}} ({{lit|paper, scissors, rock}}).<ref>{{cite web | url=https://view.genial.ly/5f582534c8db0e0d72759a70/interactive-image-te-wiki-o-te-reo-maori-2020-or-ko-ta-te-rangatira-kai-he-krero | title=Te Wiki o te Reo Māori 2020 &#124; Ko Tā te Rangatira Kai, He Kōrero | access-date=2023-06-08 | archive-date=2023-08-01 | archive-url=https://web.archive.org/web/20230801160632/https://view.genial.ly/5f582534c8db0e0d72759a70/interactive-image-te-wiki-o-te-reo-maori-2020-or-ko-ta-te-rangatira-kai-he-krero | url-status=live }}</ref>

In France, the game is sometimes called Shifumi (sometimes spelled Chifoumi).{{cn|date=February 2025}}

== Gameplay ==
{{multiple image
| align = right
| image1 = Rock-paper-scissors (rock).png
| width1 = 100
| alt1 = 
| caption1 = 
| image2 = Rock-paper-scissors (paper).png
| width2 = 100
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| caption2 = 
| image3 = Rock-paper-scissors (scissors).png
| width3 = 100
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| caption3 = 
| footer = 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!", almost exclusively localized in the United States to [[Long Island]] and some parts of New York City), a version where players say “Scissors! Paper! Rock!”, and a version where players shake their hands three times before "throwing".{{citation needed|date=November 2023}}

== History ==

===Origins===

The first known mention of the game was in the book ''{{Interlanguage link|Wuzazu|zh|3=五雜組}}''<!-- ({{zh |t=五雜組 |s=五杂组 |first=t}}) --> by the [[Ming dynasty|Ming-dynasty]] writer {{Interlanguage link|Xie Zhaozhe|zh|3=謝肇淛}} (<!-- {{zh |t=謝肇淛 |s=谢肇淛 |first=t |links=no}}; -->{{fl.}} {{circa}} 1600), who wrote that the game dated back to the time of the [[Han dynasty]] (206 BCE – 220 CE).<ref>{{cite book|last=Moore|first=Michael E.|title=Introduction to the game industry|year=2006|publisher=Pearson Prentice Hall|location=Upper Saddle River, NJ|isbn=978-0-13-168743-1|page=535|author2=Sward, Jennifer }}</ref> In the book, the game was called ''shoushiling''. [[Li Rihua]]'s <!-- ({{zh |t=李日華 |s=李日华 |first=t |links=no}}) -->book ''Note of Liuyanzhai'' <!-- ({{zh |t=六硯齋筆記 |s=六砚斋笔记 |first=t |links=no}}) --> also mentions this game, calling it ''shoushiling'' ([[Traditional Chinese characters|t]]. 手勢令; [[Simplified Chinese characters|s]]. 手势令), ''huozhitou'' ([[Traditional Chinese characters|t]]. 豁指頭; [[Simplified Chinese characters|s]]. 豁指头), or ''huaquan'' (划拳).

[[File:Mushi-ken (虫拳), Japanese rock-paper-scissors variant, from the Kensarae sumai zue (1809).jpg|thumb|300px|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.<ref name=linh95/> 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).<ref name=linh95>{{cite journal|last=Linhart|first=Sepp |title=Some Thoughts on the Ken Game in Japan: From the Viewpoint of Comparative Civilization Studies| journal=Senri Ethnological Studies| year=1995| volume=40| pages=101–124 | hdl=10502/750}}</ref>

The earliest ''sansukumi-ken'' in Japan was apparently ''mushi-ken'' (虫拳), a version imported directly from China.<ref name=linh95/><ref name=linha95-3940>{{cite book|last=Linhart|first=Sepp|title=Ceremony and Ritual in Japan|year=1995|publisher=Routledge| location=London| isbn=9780415116633| chapter=Rituality in the ken game|pages=38–41}}</ref> 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".<ref name=linh95/><ref name=linha95-3940/> (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)).<ref name=linha95-3940/>

The most popular ''sansukumi-ken'' game in Japan{{When|date=March 2024}} was ''kitsune-ken'' ([[:ja:狐拳|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.<ref name=linha98-325326>{{cite book|last=Linhart|first=Sepp|title=The Culture of Japan as Seen through Its Leisure|year=1998|publisher=SUNY Press| location=New York| isbn=9780791437919| chapter=From Kendo to Jan-ken: The Deterioration of a Game from Exoticism to Ordinariness|pages=325–326}}</ref>

[[File:Kitsune-ken (狐拳), Japanese rock-paper-scissors variant, from the Genyoku sui bento (1774).jpg|left|thumb|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 {{nihongo|''jan-ken''|じゃんけん}},<ref name=linha95-3940/> which is a variation of the Chinese games introduced in the 17th century.<ref>{{cite book|last=Sosnoski|first=Daniel|title=Introduction to Japanese culture|year=2001|publisher=Tuttle|location=Rutland|isbn=9780804820561|pages=[https://archive.org/details/introductiontoja00dani/page/44 44]|url=https://archive.org/details/introductiontoja00dani/page/44}}</ref> ''Jan-ken'' uses the rock, paper, and scissors signs<ref name=linh95 /> and is the direct source of the modern version of rock paper scissors.<ref name=linha95-3940/> 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 period|Meiji]] periods.<ref>{{cite book|last=Linhart|first=Sepp|title=Ken no bunkashi|year=1998|publisher=shoten Kadokawa|location=Tokyo|isbn=4-04-702103-2}}</ref>

=== 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.<ref>{{cite book|last=Ogawa|first=Dennis M.|title=Jan Ken Po: The World of Hawaii's Japanese Americans|year=1978|publisher=University of Hawaii Press|location=Hawaii}}</ref> Its English-language name is therefore taken from a translation of the names of the three Japanese hand-gestures for rock, paper and scissors;<ref name="長田須磨・須山名保子共編 1977.4"/> elsewhere in East Asia the open-palm gesture represents "cloth" rather than "paper".<ref>[http://my-seoul-searching.blogspot.co.uk/2009/11/kai-bai-bo.html In Korea the name of the game, Kai Bai Bo, or Kawi Bawi Bo, translates as "scissors, rock, cloth"] {{Webarchive|url=https://web.archive.org/web/20200728170214/http://www.myseoulsearching.com/2009/11/kai-bai-bo.html|date=2020-07-28}}</ref> The shape of the scissors is also adopted from the Japanese style.<ref name="長田須磨・須山名保子共編 1977.4"/>

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".<ref>{{cite journal |journal=Sydney Morning Herald |date=1921-01-07 |page=8 |title=Test Match |first=L. C. S. |last=Poidevin}}</ref> Another article, from the same year, the ''[[Washington Herald]]'' described it as a method of "Chinese gambling".<ref>{{cite journal |title=Chinese Gambling |journal=Washington Herald |date=1921-08-28 |page=28}}</ref>
In Britain in 1924 it was described in a letter to ''The Times'' as a hand game, possibly of Mediterranean origin, called "zhot".<ref>After the Rome correspondent of a British paper described the traditional Italian hand-game of ''[[morra (game)|morra]]'', which has some similarities to rock paper scissors, a brief correspondence began on the subject. One contributor described a game he had seen played in Mediterranean ports, called 'zot' or 'zhot', which was clearly identical with the modern Rock paper scissors": 'In this game the closed fist represents a stone, the open hand with fingers outstretched paper, and the closed fist with two fingers outstretched scissors...The players stand facing one another, and commence playing simultaneously by raising and lowering the right arm three times rapidly, coming to rest with the fist in any of the three above-mentioned positions. If you keep your fist closed and your opponent flings open his hand then you lose, as paper wraps up stones, and so on.' {{cite news|last=Garwood|first=G.L.P., Paymaster Lieutenant, R.N. |title=Letter to the editor|work=[[The Times]]|date=1 March 1924|page=15}}</ref>
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.<ref>{{cite news|author=Miss F.C.Pringle|title=Letter to the editor|work=[[The Times]]|date=6 March 1924|page=8}}</ref> 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 (genre)|thriller]] [[novel]] with the title ''Scissors Cut Paper'',<ref>[[Gerard Fairlie]], ''Scissors Cuts Paper'', Hodder and Stoughton, (1927)</ref> 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 [[Camp Fire Girls (novel series)|''Campfire Girls'' series]]: ''The Campfire Girls Go Motoring'' (1916) <ref>[[Camp Fire Girls (novel series)|Hildegard G. Frey]], ''The Campfire Girls Go Motoring'', A. L. Burt Company, (1916)</ref> and ''The Campfire Girls Larks and Pranks'' (1917),<ref>[[Camp Fire Girls (novel series)|Hildegard G. Frey]], ''The Campfire Girls Larks and Pranks'', A. L. Burt Company, (1917)</ref> 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,<ref>{{cite news|title=Jeux actifs et mi-actifs pouvant être joués en classe|work=La Vie au patronage|date=January 1927|page=73}}</ref> 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.<ref>'New York Times', May 22, 1932 - The ''New York Times Magazine'', article by Marion May Dilts: "COMMUTING WITH TOKYO'S SUBURBANITES; Their Morning Ritual Is Characteristically Japanese, but In Their Mode of Travel There Is Western Technique"</ref> 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 Encyclopedia|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."<ref>''[[Compton's Pictured Encyclopedia]]'', 1933, Volume 7, p. 194. [[F. E. Compton]] & Company, Chicago</ref>

== Strategies ==
[[File:Roshambo-Laos.jpg|thumb|Children in Laos playing rock paper scissors]]
[[File:Roshambo-Myanmar.jpg|thumb|Children in Myanmar playing rock paper scissors]]
It is impossible to gain an advantage over an opponent that chooses their move [[Discrete uniform distribution|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.<ref name="rpscontest"/><ref name = "bbc rps">{{cite news |url=https://www.bbc.co.uk/news/science-environment-27228416 |title=How to win at rock–paper–scissors |first=James |last=Morgan |work=BBC News |publisher=BBC |date=2 May 2014 |access-date=2 May 2014 |archive-date=2 May 2014 |archive-url=https://web.archive.org/web/20140502080443/http://www.bbc.co.uk/news/science-environment-27228416 |url-status=live }}</ref><ref>{{cite news|title=Rock-Paper-Scissors: You vs. the Computer|url=https://www.nytimes.com/interactive/science/rock-paper-scissors.html|author1=Dance, Gabriel|author2=Jackson, Tom|name-list-style=amp|access-date=2011-06-15|date=2010-10-07|work=The New York Times|archive-date=2011-04-30|archive-url=https://web.archive.org/web/20110430004735/http://www.nytimes.com/interactive/science/rock-paper-scissors.html|url-status=live}}</ref> As a result, there have been programming competitions for [[algorithm]]s that play rock paper scissors.<ref name="rpscontest">{{cite web|title=Rock Paper Scissors Programming Competition|url=http://www.rpscontest.com/|author=Knoll, Byron|access-date=2011-06-15|archive-date=2019-04-10|archive-url=https://web.archive.org/web/20190410031615/http://www.rpscontest.com/|url-status=live}}</ref><ref name="roshambo1">{{cite web|title=First International RoShamBo Programming Competition|url=https://webdocs.cs.ualberta.ca/~darse/rsb-results1.html|access-date=2011-06-15|date=1999-10-01|archive-date=2011-08-10|archive-url=https://web.archive.org/web/20110810213237/http://webdocs.cs.ualberta.ca/~darse/rsb-results1.html|url-status=dead}}</ref><ref name="roshambo2">{{cite web|title=Second International RoShamBo Programming Competition|url=https://webdocs.cs.ualberta.ca/~darse/rsbpc.html|access-date=2011-06-15|date=2001-03-20|archive-date=2011-08-07|archive-url=https://web.archive.org/web/20110807090758/http://webdocs.cs.ualberta.ca/~darse/rsbpc.html|url-status=dead}}</ref>

During tournaments, players often prepare their sequence of three gestures prior to the tournament's commencement.<ref name="Lawrence Journal-World">Steve Vockrodt, [http://www2.ljworld.com/news/2007/apr/08/student_rivals_throw_down_rock_paper_scissors_tour/ "Student rivals throw down at rock, paper, scissors tournament"] {{Webarchive|url=https://web.archive.org/web/20070428114558/http://www2.ljworld.com/news/2007/apr/08/student_rivals_throw_down_rock_paper_scissors_tour/ |date=2007-04-28 }}, ''[[Lawrence Journal-World]]'', 8 April 2007. Retrieved 13 April 2007.</ref><ref name="Fox News">Michael Y. Park, [https://www.foxnews.com/story/rock-paper-scissors-the-sport "Rock, Paper, Scissors, the Sport"], ''[[Fox News Channel|Fox News]]'', 20 March 2006. Retrieved 13 April 2007.</ref> 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|date=May 2022}}

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|date=July 2023}}

=== Algorithms ===
As a consequence of rock paper scissors programming contests, many strong algorithms have emerged.<ref name="rpscontest"/><ref name="roshambo1"/><ref name="roshambo2"/> For example, Iocaine Powder, which won the First International RoShamBo Programming Competition in 1999,<ref name="roshambo1"/> uses a heuristically designed compilation of strategies.<ref>{{cite web|title=Iocaine Powder Explained|url=http://www.ofb.net/~egnor/iocaine.html|author=Egnor, Dan|access-date=2011-06-15|date=1999-10-01|url-status=dead|archive-url=https://web.archive.org/web/20110723203327/http://www.ofb.net/~egnor/iocaine.html|archive-date=2011-07-23}}</ref> 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&nbsp;– for example, the opponent's moves, the program's own moves, or a combination of both.<ref name="werfer">{{cite web|title=Rock Paper Scissors Programming Competition entry: DNA werfer 5 L500|url=http://www.rpscontest.com/entry/109010|author=dllu|access-date=2011-06-15|date=2011-06-14|archive-date=2012-03-25|archive-url=https://web.archive.org/web/20120325184613/http://www.rpscontest.com/entry/109010|url-status=live}}</ref> There have also been other algorithms based on [[Markov chain]]s.<ref>{{cite web|title=Rock Paper Scissors Programming Competition entry: sixth-order markov chain|url=http://www.rpscontest.com/entry/34014|author=rfw|access-date=2011-06-15|date=2011-05-22|archive-date=2012-03-25|archive-url=https://web.archive.org/web/20120325184648/http://www.rpscontest.com/entry/34014|url-status=live}}</ref>

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.<ref>{{cite news| url=https://www.theguardian.com/technology/video/2012/jun/27/rock-paper-scissors-robot-video | location=London | work=The Guardian | title=Rock-paper-scissors robot wins every time – video | date=2012-06-27}}</ref><ref>{{cite web | url = http://www.k2.t.u-tokyo.ac.jp/fusion/Janken/index-e.html | title = Janken (rock-paper-scissors) robot with 100% winning rate (human-machine cooperation system) | website = The University of Tokyo | access-date = 12 January 2018 | archive-date = 12 January 2018 | archive-url = https://web.archive.org/web/20180112100934/http://www.k2.t.u-tokyo.ac.jp/fusion/Janken/index-e.html | url-status = dead }}</ref>

== Variations ==
{{Redirect-distinguish|Jack en poy|Jack Em Popoy: The Puliscredibles}}
[[File:Geisha Playing the Hand-Game Kitsune-ken (狐拳), a Japanese rock-paper-scissors variant, by Kikukawa Eizan (菊川英山).jpg|thumb|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 ===

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]]''.<ref>{{cite web |url=https://www.hancinema.net/play-muk-zzi-ppa-the-upgraded-rock-paper-scissors-30907.html |title=Play muk-zzi-ppa! The upgraded rock-paper-scissors |date=2011-06-25 |publisher=[[Hancinema]] |access-date=2014-02-06 |archive-date=2014-02-21 |archive-url=https://web.archive.org/web/20140221143748/http://www.hancinema.net/play-muk-zzi-ppa-the-upgraded-rock-paper-scissors-30907.html |url-status=live }}</ref> 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.<ref>{{cite web |url=https://medium.com/kontinentalist/how-rock-paper-scissors-is-played-around-asia-46d1d8c93be3 |title=How rock paper scissors is played around Asia |date=2019-07-29 |publisher=[[Medium (website)|Medium]] |access-date=2021-11-24 |archive-date=2021-11-25 |archive-url=https://web.archive.org/web/20211125013142/https://medium.com/kontinentalist/how-rock-paper-scissors-is-played-around-asia-46d1d8c93be3 |url-status=dead }}</ref> This variation was featured in the second season of the [[Netflix]] series ''[[Squid Game]].''

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 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|date=February 2024}}

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.<ref>{{Cite book|title=The Official Rock paper Scissors Strategy Guide|last=Walker|first=Douglas and Graham|publisher=Simon & Schuster|year=2004|isbn=0-7432-6751-6|location=Bloomington, IN|pages=[https://archive.org/details/officialrockpape00walk/page/140 140]|url=https://archive.org/details/officialrockpape00walk/page/140}}</ref>

=== Different weapons ===
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).<ref>{{Cite web|last=Kementerian Pendidikan dan Kebudayaan RI|author-link=Ministry of Education and Culture (Indonesia)|date=2020-03-10|title=Tahukah, #SahabatDikbud?|url=https://www.facebook.com/Kemdikbud.RI/posts/2686746394768117 |archive-url=https://ghostarchive.org/iarchive/facebook/119573194818796/2686746394768117 |archive-date=2022-02-26 |url-access=limited|access-date=2020-10-18|website=Facebook|language=id}}{{cbignore}}</ref> 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".<ref>{{cite web |url=https://fortheloveofplay.wordpress.com/2010/11/16/after-another-short-break-not-much-equipment-games-returns-bear-hunter-ninja/ |title=After Another Short Break, "Not Much Equipment Games" returns – Bear, Hunter, Ninja! - Knucklebones |work=Knucklebones |date=16 November 2010 |access-date=2 May 2015}}</ref> 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.<ref>{{cite web |url=http://seanthorenson.wordpress.com/2010/05/26/ninja-hunter-bear/ |title=Ninja, Hunter, Bear |work=Inklings |access-date=2 May 2015 |url-status=dead |archive-url=https://web.archive.org/web/20141223063418/http://seanthorenson.wordpress.com/2010/05/26/ninja-hunter-bear/ |archive-date=23 December 2014}}</ref> The players' choices break down as: Hunter shoots bear; Bear eats ninja; Ninja kills hunter.<ref>{{cite web |url=http://www.pigsdontfly.com/2008/04/bear-hunter-ninja.html |title=Pigs Don't Fly by Zac Martin - Digital Marketing & Entrepreneurship: + Bear Hunter Ninja |date=4 April 2008 |access-date=2 May 2015 |archive-date=16 October 2015 |archive-url=https://web.archive.org/web/20151016033657/http://www.pigsdontfly.com/2008/04/bear-hunter-ninja.html |url-status=live }}</ref>

=== Additional weapons ===
Generalized rock-paper-scissors games where the players have a choice of more than three weapons have been studied.<ref>{{cite arXiv|last=Akin|first=Ethan|eprint=1806.11241|title=Rock, Paper, Scissors, Etc—Topics in the Theory of Regular Tournaments|year=2018 |class=math.DS}}</ref> Any variation of rock paper scissors is an [[Orientation (graph theory)|oriented graph]], where the [[Vertex (graph theory)|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 [[Graph isomorphism|isomorphic]]) oriented graphs grows with the number of weapons = 3, 4, 5, ... as follows:<ref>{{citation
 | last1 = Harary | first1 = Frank | author1-link = Frank Harary | last2 = Palmer | first2 = Edgar M. | contribution = Formula 5.4.13 | location = New York | mr = 0357214 | page = 133 | publisher = Academic Press | title = Graphical Enumeration | year = 1973}}.</ref><ref name="rpsfwgame"/>
: 7, 42, 582, 21480, 2142288, 575016219, 415939243032, … {{OEIS|A001174}}.

The French game ''pierre, papier, ciseaux, puits'' (stone, paper, scissors, [[water well|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.<ref name=Umbhauer>{{cite book|title=Game Theory and Exercises|last=Umbhauer|first=Gisèle|isbn=978-1-3173-6299-9|page=340|publisher=Routledge|date=2016}}</ref>

{| class="wikitable"
|+ "pierre, papier, ciseaux, puits";<br> + means that the row player "beats", − means "is beaten" and O means tie
! {{diagonal split header|<br />Row<br />player|Opponent}}
! style=min-width:5em | stone
! style=min-width:5em | paper
! style=min-width:5em | scissors
! style=min-width:5em | well
! nowrap | Optimal strategy for<br />the row player<ref name=Umbhauer/>
|- style="text-align: center;"
! scope=row | stone
          || O     || −     || +        || −    || <math>0</math>
|- style="text-align: center;"
! scope=row | paper
           || +     || O     || −        || +    || <math>\frac{1}{3}</math>
|- style="text-align: center;"
! scope=row | scissors
           || −     || +     || O        || −    || <math>\frac{1}{3}</math>
|- style="text-align: center;"
! scope=row | well
           || +     || −     || +        || O    || <math>\frac{1}{3}</math>
|}
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.<ref>{{cite web | title = RPSx | url = http://www.umop.com/rps.htm | access-date = 2011-06-14 | archive-date = 2018-10-24 | archive-url = https://web.archive.org/web/20181024085608/http://www.umop.com/rps.htm | url-status = live }}</ref> 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.<ref>{{cite web | title= Rock Paper Scissors Graphs | url= http://www.kreativekorp.com/miscpages/rps/ | author-first= Rebecca G. | author-last= Bettencourt | author-link= Rebecca G. Bettencourt | access-date= 2017-04-06 | archive-date= 2017-04-07 | archive-url= https://web.archive.org/web/20170407055323/http://www.kreativekorp.com/miscpages/rps/ | url-status= live }}</ref>
[[File:Pierre ciseaux feuille lézard spock aligned.svg|thumb|Rock paper scissors lizard Spock gestures]]
One popular five-weapon expansion is "{{visible anchor|rock paper scissors Spock lizard}}", invented by Sam Kass and Karen Bryla,<ref>{{cite web | title = Original Rock-Paper-Scissors-Spock-Lizard Page | url = http://www.samkass.com/theories/RPSSL.html | author = Sam Kass | access-date = 2009-03-11 | archive-date = 2010-11-13 | archive-url = https://web.archive.org/web/20101113135208/http://www.samkass.com/theories/RPSSL.html | url-status = live }}</ref> 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<ref name="TimesSpockLizard">{{cite news |url=https://www.thetimes.co.uk/article/and-paper-scissors-5pz9q0xkxct |title=... and paper scissors |date=11 June 2005 |access-date=2009-06-09 |archive-url=https://web.archive.org/web/20100531231332/http://www.timesonline.co.uk/tol/comment/leading_article/article1080425.ece |archive-date=31 May 2010 |url-status=dead |newspaper=The Times }}{{subscription required}}</ref> and was later the subject of an [[List of The Big Bang Theory episodes#ep25|episode]] of the American sitcom ''[[The Big Bang Theory]]'' in 2008 (as ''rock-paper-scissors-lizard-Spock'').<ref>{{cite web |last=Lorre |first=Chuck |author-link=Chuck Lorre |title=The Big Bang Theory Video&nbsp;— Rock, Paper, Scissors, Lizard, Spock&nbsp;— CBS.com |url=http://www.cbs.com/shows/big_bang_theory/video/926519421/the-big-bang-theory-rock-paper-scissors-lizard-spock |publisher=[[CBS]] |format=video |access-date=4 September 2012 |archive-url=https://web.archive.org/web/20180730080428/https://www.cbs.com/shows/big_bang_theory/video/926519421/the-big-bang-theory-rock-paper-scissors-lizard-spock/ |archive-date=30 July 2018 |url-status=dead }}</ref>
{| class="wikitable"
|+ Rock-Paper-Scissors-Spock-Lizard;<br> + means that the row player "beats", − means "is beaten" and O means tie
! {{diagonal split header|<br />Row<br />player|Opponent}}
! style=min-width:5em | rock
! style=min-width:5em | paper
! style=min-width:5em | scissors
! style=min-width:5em | Spock
! style=min-width:5em | lizard
! nowrap | Optimal strategy<br />for row player
|- style="text-align: center;"
! scope=row | rock
           || O     || −     || +        || −    || +      || <math>\frac{1}{5}</math>
|- style="text-align: center;"
! scope=row | paper
           || +     || O     || −        || +    || −      || <math>\frac{1}{5}</math>
|- style="text-align: center;"
! scope=row | scissors
           || −     || +     || O        || −    || +      || <math>\frac{1}{5}</math>
|- style="text-align: center;"
! scope=row | Spock
           || +     || −     || +        || O    || −      || <math>\frac{1}{5}</math>
|- style="text-align: center;"
! scope=row | lizard
           || −     || +     || −        || +    || O      || <math>\frac{1}{5}</math>
|}
[[File:Rpsfw game.svg|300px|thumb|right|Oriented graph of Rock-Paper-Scissors-Fire-Water]]
A [[Game theory|game-theoretic analysis]] showed that 4 variants of 582 possible variations using 5 different weapons have non-trivial [[Strategy (game theory)#Mixed strategy|mixed strategy equilibria]].<ref name="rpsfwgame">{{cite journal |last1=Tagiew |first1=Rustam |title=Towards a Framework for Management of Strategic Interaction |journal=Proceedings of the International Conference on Agents and Artificial Intelligence |date=2009 |issue=ICAART |pages=587–590 |url=https://www.researchgate.net/publication/221539739 |access-date=2020-01-27 |archive-date=2020-07-28 |archive-url=https://web.archive.org/web/20200728170217/https://www.researchgate.net/publication/221539739_Towards_a_Framework_for_Management_of_Strategic_Interaction |url-status=live }}</ref> 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 <math>\frac{1}{9}</math> of the time and <math>\frac{1}{3}</math> of the time for fire and water. Nevertheless, experiments show that people underuse water and overuse rock, paper, and scissors in this game.<ref>{{cite book |last1=Tagiew |first1=Rustam |title=AI*IA 2009: Emergent Perspectives in Artificial Intelligence |chapter=Hypotheses about Typical General Human Strategic Behavior in a Concrete Case |series=Lecture Notes in Computer Science |date=2009 |volume=5883 |pages=476–485 |publisher=Springer |location=Berlin, Heidelberg |doi=10.1007/978-3-642-10291-2_48 |bibcode=2009LNCS.5883..476T |isbn=978-3-642-10290-5  | issn=0302-9743}}</ref>
{| class="wikitable"
|+ Rock-Paper-Scissors-Fire-Water;<br> + means that the row player "beats", − means "is beaten" and O means tie
! {{diagonal split header|<br />Row<br />player|Opponent}}
! style=min-width:5em | rock
! style=min-width:5em | paper
! style=min-width:5em | scissors
! style=min-width:5em | fire
! style=min-width:5em | water
! nowrap | Optimal strategy<br />for row player<ref name="rpsfwgame"/>
|- style="text-align: center;"
! scope=row | rock
           || O     || −     || +        || −    || +      || <math>\frac{1}{9}</math>
|- style="text-align: center;"
! scope=row | paper
           || +     || O     || −        || −    || +      || <math>\frac{1}{9}</math>
|- style="text-align: center;"
! scope=row | scissors
           || −     || +     || O        || −    || +      || <math>\frac{1}{9}</math>
|- style="text-align: center;"
! scope=row | fire
           || +     || +     || +        || O    || −      || <math>\frac{1}{3}</math>
|- style="text-align: center;"
! scope=row | water
           || −     || −     || −        || +    || O      || <math>\frac{1}{3}</math>
|}

== Analogues in real life ==

=== Lizard mating strategies ===
{{Main|Common side-blotched lizard#Mating}}
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.<ref>{{cite web | title = The rock-paper-scissors game and the evolution of alternative male strategies | url = http://bio.research.ucsc.edu/~barrylab/lizardland/male_lizards.overview.html | author = Sinervo, Barry | access-date = 2006-08-20 | date = 2001-02-20 | archive-url = https://web.archive.org/web/20190211132220/http://bio.research.ucsc.edu/~barrylab/lizardland/male_lizards.overview.html | archive-date = 2019-02-11 | author-link = Barry Sinervo }}</ref><ref>{{cite web | title = The Games Lizards Play | url = http://7thavenueproject.com/post/451026680/barry-sinervo-lizards-and-evolution | author = Barry Sinervo on the 7th Avenue Project Radio Show | author-link = Barry Sinervo on the 7th Avenue Project Radio Show | access-date = 2010-03-25 | archive-date = 2011-04-24 | archive-url = https://web.archive.org/web/20110424205323/http://7thavenueproject.com/post/451026680/barry-sinervo-lizards-and-evolution | url-status = live }}</ref>

=== Bacteria ===
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]].<ref>{{cite journal|last=Kerr|first=Benjamin|author2=Riley, Margaret A. |author3=Feldman, Marcus W. |author4= Bohannan, Brendan J. M. |title=Local dispersal promotes biodiversity in a real-life game of rock–paper–scissors|journal=Nature|date=11 July 2002|volume=418|issue=6894|pages=171–174|doi=10.1038/nature00823|pmid=12110887|bibcode=2002Natur.418..171K|s2cid=4348391}}</ref> Additional ''in vitro'' results demonstrate rock paper scissors dynamics in additional species of bacteria.<ref>{{cite journal|last=Pátková|first=Irena|author2=Čepl, Jaroslav J |author3=Rieger, Tomáš |author4=Blahůšková, Anna |author5=Neubauer, Zdeněk |author6= Markoš, Anton |title=Developmental plasticity of bacterial colonies and consortia in germ-free and gnotobiotic settings|journal=BMC Microbiology|date=1 January 2012|volume=12|issue=1 |pages=178|doi=10.1186/1471-2180-12-178|pmid=22894147|pmc=3583141 |doi-access=free }}</ref> Biologist Benjamin C. Kirkup Jr. demonstrated that these antibiotics, [[bacteriocin]]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.<ref>{{cite journal|last=Kirkup|first=Benjamin C.|author2=Riley, Margaret A. |title=Antibiotic-mediated antagonism leads to a bacterial game of rock–paper–scissors in vivo|journal=Nature|date=25 March 2004|volume=428|issue=6981|pages=412–414|doi=10.1038/nature02429|pmid=15042087|bibcode=2004Natur.428..412K|s2cid=4412745}}</ref>

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.<ref>{{cite journal|last=Adami|first=Christoph|author2=Schossau, Jory |author3=Hintze, Arend |title=Evolution and stability of altruist strategies in microbial games|journal=Physical Review E|date=1 January 2012|volume=85|issue=1|pages=011914|doi=10.1103/PhysRevE.85.011914|pmid=22400598|arxiv=1012.0276|bibcode=2012PhRvE..85a1914A|s2cid=2587810}}</ref> Models of evolution demonstrate how intragenomic competition can lead to rock paper scissors dynamics from a relatively general evolutionary model.<ref>{{cite journal|last=Rankin|first=D. J.|author2=Turner, L. A. |author3=Heinemann, J. A. |author4= Brown, S. P. |title=The coevolution of toxin and antitoxin genes drives the dynamics of bacterial addiction complexes and intragenomic conflict|journal=Proceedings of the Royal Society B: Biological Sciences|date=11 July 2012|volume=279|issue=1743|pages=3706–3715|doi=10.1098/rspb.2012.0942 |pmid=22787022 |pmc=3415908}}</ref> The general nature of this basic non-transitive model is widely applied in theoretical biology to explore bacterial ecology and evolution.<ref>{{cite journal|last=Bucci|first=Vanni|author2=Nadell, Carey D. |author3=Xavier, João B. |title=The Evolution of Bacteriocin Production in Bacterial Biofilms|journal=The American Naturalist|date=1 December 2011|volume=178|issue=6|pages=E162–E173|doi=10.1086/662668|pmid=22089878|s2cid=25361931}}</ref><ref>{{cite journal|doi=10.1103/PhysRevE.84.021912|pmid=21929025|title=Effects of competition on pattern formation in the rock-paper-scissors game|year=2011|last1=Jiang|first1=Luo-Luo|last2=Zhou|first2=Tao|last3=Perc|first3=Matjaž|last4=Wang|first4=Bing-Hong|journal=Physical Review E|volume=84|issue=2|pages=021912|arxiv=1108.1790|bibcode=2011PhRvE..84b1912J|s2cid=6375624}}</ref>

=== Mechanical devices and geometrical constructions ===
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".<ref>{{cite web| url = http://www.popsci.com/technology/article/2013-06/elaborate-history-how-wedges-ruined-battlebots| title = Atherton, K. D. (2013). A brief history of the demise of battle bots. Popular science.| date = 19 June 2013| access-date = 1 December 2018| archive-date = 13 September 2017| archive-url = https://web.archive.org/web/20170913013037/http://www.popsci.com/technology/article/2013-06/elaborate-history-how-wedges-ruined-battlebots| url-status = live}}</ref>

== Instances of usage ==
=== American court case ===
In 2006, American federal judge [[Gregory A. Presnell|Gregory Presnell]] from the [[United States District Court for the Middle District of Florida|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 (law)|deposition]] using the game of rock paper scissors.<ref>{{cite news | url = http://seattletimes.nwsource.com/html/nationworld/2003052251_game10.html | title = Exasperated judge resorts to child's game | agency = Associated Press | date = 2006-06-26 | access-date = 2006-08-20 | work = The Seattle Times | archive-date = 2006-06-14 | archive-url = https://web.archive.org/web/20060614003222/http://seattletimes.nwsource.com/html/nationworld/2003052251_game10.html | url-status = live }}</ref><ref>{{Cite news|url=https://www.nytimes.com/2006/06/09/us/09judge.html|title=Lawyers Won't End Squabble, So Judge Turns to Child's Play|last=Liptak|first=Adam|date=2006-06-09|newspaper=The New York Times|issn=0362-4331|access-date=2016-08-10|archive-date=2017-05-10|archive-url=https://web.archive.org/web/20170510081547/http://www.nytimes.com/2006/06/09/us/09judge.html|url-status=live}}</ref> The ruling in ''Avista Management v. Wausau Underwriters'' stated:

{{Blockquote|Upon consideration of the Motion&nbsp;– the latest in a series of [[Gordian knot]]s that the parties have been unable to untangle without enlisting the assistance of the federal courts&nbsp;– 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.<ref>{{cite news| url=https://money.cnn.com/2006/06/07/magazines/fortune/judgerps_fortune/index.htm| publisher=CNN.com| access-date=2006-06-08| title=Order of the court: Avista Management vs. Wausau Underwriters Insurance Co| date=June 7, 2006| first=Gregory| last=Presnell| url-status=live| archive-url=https://web.archive.org/web/20150216120044/https://archive.fortune.com/2006/06/07/magazines/fortune/judgerps_fortune/index.htm| archive-date=2015-02-16}}</ref>}}

=== Auction house selection ===
[[Image:Les Grands Arbres au Jas de Bouffan, par Paul Cézanne, Yorck.jpg|thumb|[[Paul Cézanne|Cézanne]]'s ''Large Trees Under the Jas de Bouffan'' sold for $11,776,000 at [[Christie's]] in 2005.<ref name="CityReview">[http://www.thecityreview.com/s05cimp1.html Art/Auctions logo, Impressionist & Modern Art, Christie's, 7 pm, May 4, 2005, Sale 1514] {{Webarchive|url=https://web.archive.org/web/20080127185532/http://www.thecityreview.com/s05cimp1.html |date=January 27, 2008 }}.</ref>]]
In 2005, when Takashi Hashiyama, CEO of Japanese television equipment manufacturer [[Maspro Denkoh]], decided to auction off the collection of [[Impressionism|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".<ref>{{Cite news
 | last =Vogel
 | first =Carol
 | title =Rock, Paper, Payoff: Child's Play Wins Auction House an Art Sale
 | newspaper =[[The New York Times]]
 | date =April 29, 2005
 | url =https://www.nytimes.com/2005/04/29/arts/design/29scis.html
 | access-date =February 20, 2017
 | archive-date =March 9, 2015
 | archive-url =https://web.archive.org/web/20150309052605/http://www.nytimes.com/2005/04/29/arts/design/29scis.html?
 | url-status =live
 }}</ref> 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 referee, upon being without a coin for the pregame [[Coin flipping|coin toss]], had the team captains play rock paper scissors to determine which team would [[Kick-off (association football)|kick-off]]. The referee was subsequently suspended for three weeks by [[The Football Association]].<ref>{{cite web |url=https://deadspin.com/soccer-ref-suspended-three-weeks-for-using-rock-paper-s-1830446662 |title=Soccer Ref Suspended Three Weeks For Using Rock-Paper-Scissors Instead Of Coin Flip |first=Lauren |last=Theisen |website=[[Deadspin]] |date=November 14, 2018 |access-date=November 15, 2018 |archive-date=November 15, 2018 |archive-url=https://web.archive.org/web/20181115095935/https://deadspin.com/soccer-ref-suspended-three-weeks-for-using-rock-paper-s-1830446662 |url-status=live }}</ref>

=== Play by chimpanzees ===
In Japan, researchers have taught [[chimpanzee]]s to identify winning hands according to the rules of rock paper scissors.<ref>{{cite news|url=https://www.bbc.com/news/av/science-environment-40946194/chimps-can-play-rock-paper-scissors|title=Chimps can play rock-paper-scissors|work=BBC News|access-date=11 December 2017|archive-date=27 December 2017|archive-url=https://web.archive.org/web/20171227031016/http://www.bbc.com/news/av/science-environment-40946194/chimps-can-play-rock-paper-scissors|url-status=live}}</ref>

=== 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]] and single dominant type of unit.<ref name="egenfeldt-nielsen">{{cite book|title=Understanding video games: the essential introduction|last=Egenfeldt-Nielsen|first=Simon|author2=Jonas Heide Smith|author3=Susana Pajares Tosca|publisher=Taylor & Francis|year=2008|isbn=978-0-415-97721-0|page=103}}</ref>

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 (video game series)|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.<ref>{{cite web|url=https://www.vg247.com/2017/06/26/pokemon-go-type-chart-strength-weakness-effectiveness-type-pokemon-battles-explained/|title=Pokemon Go type chart - type strength, weakness and effectiveness for Pokemon battles explained - VG247|date=26 June 2017|access-date=4 March 2018|archive-date=4 March 2018|archive-url=https://web.archive.org/web/20180304233524/https://www.vg247.com/2017/06/26/pokemon-go-type-chart-strength-weakness-effectiveness-type-pokemon-battles-explained/|url-status=dead}}</ref> 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 ==
[[File:rps2010 2.jpg|thumb|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 ===

Started in 2015, the WRPSA has hosted Professional Rock Paper Scissors Tournaments all around the world.<ref>{{Cite web|last=Betuel|first=Emma|title=The best rock-paper-scissors players know how to win without luck|url=https://www.inverse.com/mind-body/rock-paper-scissors-not-sports|access-date=2021-04-07|website=Inverse|date=5 August 2020|language=en|archive-date=2021-03-01|archive-url=https://web.archive.org/web/20210301010627/https://www.inverse.com/mind-body/rock-paper-scissors-not-sports|url-status=live}}</ref><ref>{{Cite web|date=2021-01-08|title=Playing to Win|url=https://www.timeforkids.com/g56/playing-to-win-2/|access-date=2021-04-07|website=Time for Kids|language=en|archive-date=2021-04-21|archive-url=https://web.archive.org/web/20210421071820/https://www.timeforkids.com/g56/playing-to-win-2/|url-status=live}}</ref><ref>{{Cite web|date=2021-02-09|title=Play to Win|url=https://www.timeforkids.com/g2/play-to-win/|access-date=2021-04-07|website=Time for Kids|language=en|archive-date=2021-04-21|archive-url=https://web.archive.org/web/20210421081814/https://www.timeforkids.com/g2/play-to-win/|url-status=live}}</ref><ref>{{Cite web|title=Hour 3: Ken "Whitey" Watson by Keyshawn, JWill & Zubin|url=https://www.podchaser.com/podcasts/keyshawn-jwill-zubin-130990/episodes/hour-3-ken-whitey-watson-30520248|access-date=2021-04-07|website=Podchaser|language=en|archive-date=2021-06-18|archive-url=https://web.archive.org/web/20210618083708/https://www.podchaser.com/podcasts/keyshawn-jwill-zubin-130990/episodes/hour-3-ken-whitey-watson-30520248|url-status=live}}</ref><ref>{{Cite web|last=|date=2016-08-04|title=About Us {{!}} The World Rock Paper Scissors Association|url=https://www.wrpsa.com/about/|access-date=2021-04-07|language=en-US|archive-date=2021-04-16|archive-url=https://web.archive.org/web/20210416151356/https://www.wrpsa.com/about/|url-status=live}}</ref>

=== World Rock Paper Scissors Society ===
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.<ref>{{cite news
| date = 2004-12-10
| url = https://www.washingtontimes.com/news/2004/dec/10/20041210-120729-4008r/
| title = Fists fly in game of strategy
| first = Patrick
| last = Hruby
| newspaper = [[The Washington Times]]
| access-date = 2006-08-20
| archive-date = 2009-02-10
| archive-url = https://web.archive.org/web/20090210081054/http://www.washingtontimes.com/news/2004/dec/10/20041210-120729-4008r/
| url-status = live
}}</ref><ref>{{cite news
| title = 2003 World Rock Paper Scissors Championship
| url = https://www.npr.org/templates/story/story.php?storyId=1477870
| date = 2003-10-24
| work = All Things Considered
| publisher = [[National Public Radio]]
| access-date = 2006-08-20
| archive-date = 2006-09-16
| archive-url = https://web.archive.org/web/20060916193934/http://www.npr.org/templates/story/story.php?storyId=1477870
| url-status = live
}}</ref><ref>{{cite news
| url = https://www.cbsnews.com/news/rock-paper-scissors-a-sport/
| title = Rock, Paper, Scissors A Sport?
| date = 2003-10-23
| work = CBS News
| access-date = 2006-08-20
| archive-date = 2015-11-18
| archive-url = https://web.archive.org/web/20151118023211/http://www.cbsnews.com/news/rock-paper-scissors-a-sport/
| url-status = live
}}</ref><ref>{{cite news
| url = https://www.usatoday.com/news/offbeat/2003-10-27-rock-paper_x.htm
| title = Rock Paper Scissors contest being held
| agency = Associated Press
| date = 2003-10-27
| access-date = 2006-08-20
| work = USA Today
| archive-date = 2006-06-14
| archive-url = https://web.archive.org/web/20060614075124/http://www.usatoday.com/news/offbeat/2003-10-27-rock-paper_x.htm
| url-status = live
}}</ref><ref>{{cite news
 |url          = https://www.foxnews.com/story/rock-paper-scissors-the-sport
 |title        = Rock, Paper, Scissors, the Sport
 |first        = Michael Y.
 |last         = Park
 |publisher    = [[Fox News Channel|Fox News]]
 |date         = 2006-03-20
 |access-date   = 2006-08-20
 |archive-url  = https://web.archive.org/web/20121021040327/http://www.foxnews.com/story/0,2933,188380,00.html
 |archive-date = 2012-10-21
 |url-status     = live
}}</ref> WRPS events were noted for their large cash prizes, elaborate staging, and colorful competitors.<ref>{{cite web | url = http://www.worldrps.com/index.php?option=com_gallery2&Itemid=30 | title = Gallery | work = World RPS society | date = 2005-11-13 | access-date = 2006-08-20 |archive-url = https://web.archive.org/web/20060315203450/http://www.worldrps.com/index.php?option=com_gallery2&Itemid=30 <!-- Bot retrieved archive --> |archive-date = 2006-03-15}}</ref>
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.<ref>{{cite news |last=Crick |first=Jennifer |url=https://money.cnn.com/magazines/fortune/fortune_archive/2005/06/13/8262549/index.htm |title=HAND JIVE - 13 June 2005 |publisher=Money.cnn.com |date=2005-06-13 |access-date=2009-06-05 |archive-date=2008-09-07 |archive-url=https://web.archive.org/web/20080907171906/http://money.cnn.com/magazines/fortune/fortune_archive/2005/06/13/8262549/index.htm |url-status=live }}</ref><ref>{{cite web|url=http://www.stanley-paul.com/index.php?option=com_gallery2&Itemid=30&g2_view=core.ShowItem&g2_itemId=16 |title=World RPS Society - 2004 Champion Lee Rammage crushes a pair of Scissors |publisher=Stanley-paul.com |date=2005-11-13 |access-date=2009-06-05}} {{Dead link|date=October 2010|bot=H3llBot}}</ref> The 2007 tournament was won by Andrea Farina.<ref>{{cite web|url=http://cnews.canoe.ca/CNEWS/WeirdNews/2007/10/15/4577669-sun.html|title=Rock Paper Scissors crowns a queen as its champ|author=Canoe inc.|work=canoe.com|access-date=2 May 2015|url-status=usurped|archive-url=https://archive.today/20120708095757/http://cnews.canoe.ca/CNEWS/WeirdNews/2007/10/15/4577669-sun.html|archive-date=8 July 2012}}</ref> The last tournament hosted by the World RPS Society was in Toronto, Canada, on November 14, 2009.<ref>{{Cite web|url=http://worldrps.com/world-championships/|title=World RPS Society World Championships|archive-url=https://web.archive.org/web/20181116124058/http://worldrps.com/world-championships/|archive-date=16 November 2018|access-date=2016-05-10}}</ref>

=== UK championships ===
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.<ref>{{cite news|url=https://news.bbc.co.uk/1/hi/england/devon/8072439.stm|title=Pub hosts UK 'rock' championship|date=28 May 2009|work=BBC News|access-date=2009-05-28|archive-url=https://web.archive.org/web/20090531124811/http://news.bbc.co.uk/1/hi/england/devon/8072439.stm|archive-date=31 May 2009|url-status=dead|df=dmy-all}}</ref>

=== USARPS tournaments ===
[[USA Rock Paper Scissors League]] is sponsored by [[Anheuser-Busch brands#Bud Light|Bud Light]]. Leo Bryan Pacis was the first commissioner of the USARPS.{{citation needed|date=December 2015}} Cody Louis Brown was elected as the second commissioner of the USARPS in 2014.{{citation needed|date=December 2015}}

In April 2006, the inaugural USARPS Championship was held in [[Las Vegas Strip|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.<ref>{{cite web |date=2008-08-27 |url=https://www.irishexaminer.com/breaking/ireland/mhqlojkfidsn/ |title=Belfast man tops world at rock, paper, scissors &#124; Irish Examiner |publisher=Examiner.ie |access-date=2009-06-05 |archive-date=2012-05-15 |archive-url=https://web.archive.org/web/20120515220959/http://www.irishexaminer.com/breaking/ireland/mhqlojkfidsn/ |url-status=dead }}</ref>

=== 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]], 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]] 2014 in [[Indianapolis]], Indiana, United States, on 17 August 2014.<ref>{{cite web|url=http://www.guinnessworldrecords.com.au/world-records/3000/largest-tournament-of-rock-paper-scissors|title=Home|access-date=25 May 2017|archive-date=12 October 2014|archive-url=https://web.archive.org/web/20141012090817/http://www.guinnessworldrecords.com.au/world-records/3000/largest-tournament-of-rock-paper-scissors|url-status=live}}</ref>

=== World Series ===
Former [[Celebrity Poker Showdown]] host and USARPS Head Referee<ref>{{cite web|url=http://www.usarps.com/tourney-info/roshs-blog/article/view/master-roshs-analysis-of-the-final-match/97/|title=Master Rosh's Analysis of the Final Match|date=2005-06-28|access-date=2009-07-31|work=USARPS Leagues|publisher=USARPS|url-status=dead|archive-url=https://web.archive.org/web/20110717175551/http://www.usarps.com/tourney-info/roshs-blog/article/view/master-roshs-analysis-of-the-final-match/97/|archive-date=2011-07-17}}</ref> [[Phil Gordon (poker player)|Phil Gordon]] has hosted an annual $500 World Series of Rock Paper Scissors event in conjunction with the [[World Series of Poker]] since 2005.<ref>{{cite news|url=https://www.nytimes.com/2007/05/14/world/americas/14iht-rock.1.5699920.html|title=Las Vegas's latest game: Rock, paper, scissors|last=Friess|first=Steven|newspaper=NY Times|date=2007-05-14|access-date=2009-07-23|archive-date=2014-12-07|archive-url=https://web.archive.org/web/20141207134529/http://www.nytimes.com/2007/05/14/world/americas/14iht-rock.1.5699920.html?|url-status=live}}</ref> The winner of the WSORPS receives an entry into the [[List of World Series of Poker Main Event champions|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.<ref>{{cite web|url=https://www.espn.com/espn/print?id=2540622&type=blogEntry|title=Where's Annie?|work=ESPN.com|date=2006-08-05|access-date=2009-07-24|archive-date=2017-07-08|archive-url=https://web.archive.org/web/20170708092135/http://www.espn.com/espn/print?id=2540622&type=blogEntry|url-status=live}}</ref> The tournament is taped by ESPN and highlights are covered during "The Nuts" section of ESPN's annual WSOP broadcast.<ref>{{cite web|url=https://www.pokernews.com/news/2005/06/the-real-championship-wsop.htm|title=The REAL championship at the World Series of Poker|last=Caldwell|first=John|publisher=Poker News|date=2005-06-15|access-date=2009-07-24|archive-date=2009-06-21|archive-url=https://web.archive.org/web/20090621064223/http://www.pokernews.com/news/2005/06/the-real-championship-wsop.htm|url-status=live}}</ref><ref>{{cite web|url=http://news.pokerpages.com/index.php?option=com_simpleblog&task=view&id=86|title=WSOP Schedule Whiplash|date=2005-06-14|access-date=2009-07-24|publisher=Poker Pages|archive-date=2009-08-05|archive-url=https://web.archive.org/web/20090805211211/http://news.pokerpages.com/index.php?option=com_simpleblog&task=view&id=86|url-status=dead}}</ref><ref>{{cite web|url=http://pokerworks.com/blogs/craigsjournal/2006/07/27/exclusive-coverage-roshambo-the-rematch/ |title=EXCLUSIVE COVERAGE: Roshambo&nbsp;— The Rematch |last=Craig |first=Michael |publisher=Pokerworks |access-date=2009-07-21 |url-status=dead |archive-url=https://web.archive.org/web/20090805095547/http://pokerworks.com/blogs/craigsjournal/2006/07/27/exclusive-coverage-roshambo-the-rematch/ |archive-date=2009-08-05 }}</ref> 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!]]''. 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.<ref>{{Cite web |url=http://www.gmanetwork.com/entertainment/tv/eat_bulaga/57015/eat-bulaga-judy-ann-santos-tinalo-ang-kapatid-sa-jackpot-en-poy/video/ |title=Eat Bulaga: Judy Ann Santos, tinalo ang kapatid sa Jackpot en Poy &#124; Eat Bulaga &#124; TV &#124; GMA Entertainment - Online Home of Kapuso Shows and Stars - Video |access-date=2017-03-06 |archive-date=2017-03-06 |archive-url=https://web.archive.org/web/20170306211900/http://www.gmanetwork.com/entertainment/tv/eat_bulaga/57015/eat-bulaga-judy-ann-santos-tinalo-ang-kapatid-sa-jackpot-en-poy/video/ |url-status=dead }}</ref><ref>{{Cite news|url=https://www.rappler.com/entertainment/news/165186-ph-senators-eat-bulaga|title=WATCH: PH senators on 'Eat Bulaga'|work=Rappler|access-date=2017-07-15|language=en|archive-date=2017-03-29|archive-url=https://web.archive.org/web/20170329114226/http://www.rappler.com/entertainment/news/165186-ph-senators-eat-bulaga|url-status=live}}</ref><ref>{{Cite news|url=http://www.philstar.com/entertainment/2017/03/20/1682731/happily-resettled-back-home|title=Happily resettled back home|last=Lo|first=Ricky|work=philstar.com|access-date=2017-07-15|archive-date=2017-05-06|archive-url=https://web.archive.org/web/20170506160109/http://www.philstar.com/entertainment/2017/03/20/1682731/happily-resettled-back-home|url-status=live}}</ref>

== See also ==
{{Portal|Games}}
* [[Chopsticks (hand game)]]
* [[Matching pennies]], the binary equivalent
* [[Morra (game)]], another hand game for deciding trivial matters
* [[Intransitive dice]]
* [[Evolutionary game theory#Rock paper scissors|Rock paper scissors and human social cyclic behavior]]
* [[Simultaneous action selection]]
* [[Strategy (game theory)#Mixed strategy|Mixed strategy]]

== References ==
'''Notes'''
{{Reflist}}

'''Bibliography'''
{{Refbegin|colwidth=30em}}
<!-- Genetica 112–113: 417–434 -->
* {{cite journal | last1 = Alonzo | first1 = Suzanne H. | last2 = Sinervo | first2 = Barry | year = 2001 | title = Mate choice games, context-dependent good genes, and genetic cycles in the side-blotched lizard, ''Uta stansburiana'' | journal = Behavioral Ecology and Sociobiology | volume = 49 | issue = 2–3| pages = 176–186 | doi = 10.1007/s002650000265 | bibcode = 2001BEcoS..49..176A | s2cid = 23799664 }}
* 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)
* [[Alice Gomme|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)
* [[Iona and Peter Opie|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.)
* {{cite journal | last1 = Sinervo | first1 = Barry | year = 2001 | title = Runaway social games, genetic cycles driven by alternative male and female strategies, and the origin of morphs | journal = Genetica | volume = 112–113 | issue = 1| pages = 417–434 | doi = 10.1023/A:1013360426789 | pmid = 11838779 | s2cid = 20046789 }}
* {{cite journal | last1 = Sinervo | first1 = Barry | last2 = Clobert | first2 = Jean | year = 2003 | title = Morphs, Dispersal Behavior, Genetic Similarity, and the Evolution of Cooperation | journal = [[Science (journal)|Science]] | volume = 300 | issue = 5627| pages = 1949–1951 | doi = 10.1126/science.1083109 | bibcode = 2003Sci...300.1949S | pmid=12817150| s2cid = 25573262 }}
* {{cite journal | last1 = Sinervo | first1 = Barry | last2 = Lively | first2 = C. M. | year = 1996 | title = The Rock-Paper-Scissors Game and the evolution of alternative male strategies | journal = [[Nature (journal)|Nature]] | volume = 380 | issue = 6571| pages = 240–243 | doi = 10.1038/380240a0 | bibcode = 1996Natur.380..240S | s2cid = 205026253 }}
* {{cite journal | last1 = Sinervo | first1 = Barry | last2 = Zamudio | first2 = K. R. | year = 2001 | title = The Evolution of Alternative Reproductive Strategies: Fitness Differential, Heritability, and Genetic Correlation Between the Sexes | journal = Journal of Heredity | volume = 92 | issue = 2| pages = 198–205 | doi = 10.1093/jhered/92.2.198 | pmid = 11396579 | doi-access = free }}
* {{cite journal | last1 = Sogawa | first1 = Tsuneo | year = 2000 | title = Janken | journal = Monthly Sinica | volume = 11 | issue = 5| language = ja }}
* Baldwin, Wyatt (2017) [https://www.amazon.com/Rock-Paper-Scissors-Handbook-Comprehensive/dp/1521785414/ref=sr_1_8?ie=UTF8&qid=1515983612&sr=8-8&keywords=rock+paper+scissors+book The Official Rock Paper Scissors Handbook] {{Webarchive|url=https://web.archive.org/web/20200728170224/https://www.amazon.com/Rock-Paper-Scissors-Handbook-Comprehensive/dp/1521785414/ref=sr_1_8?ie=UTF8&qid=1515983612&sr=8-8&keywords=rock+paper+scissors+book |date=2020-07-28 }}. ''The Official Strategy Guide of the [https://www.wrpsa.com World Rock Paper Scissors Association] {{Webarchive|url=https://web.archive.org/web/20180115184527/http://www.wrpsa.com/ |date=2018-01-15 }}''
* Walker, Douglas & Walker, Graham (2004) ''The Official Rock Paper Scissors Strategy Guide''. Fireside. (strategy, tips and culture from the World Rock Paper Scissors Society).
{{Refend}}

== External links ==
{{Commons category|Rock Paper Scissors}}
{{Wiktionary|じゃんけん}}
{{Spoken Wikipedia|Rock, Paper, Scissors.ogg|date=2006-07-14}}
* {{cite news | url = https://www.forbes.com/execpicks/fyi/2005/0407/061.html | title = Throwing for The Gold | access-date = 2007-04-09 | last = Abrams | first = Michael | date = 2004-07-05 | work = Pursuits | publisher = [[Forbes]] FYI | archive-date = 2007-12-17 | archive-url = https://web.archive.org/web/20071217190808/http://www.forbes.com/execpicks/fyi/2005/0407/061.html | url-status = dead }}
* {{cite web | url = https://www.rollingstone.com/culture/news/hand-to-hand-combat-20040107 | title = Hand to Hand Combat: Down and dirty at the World Rock Paper Scissors Championship | access-date = 2009-03-30 | last = Hegan | first = Ken | date = 2004-01-07 | publisher = Rolling Stone Feature Article | archive-date = 2012-04-23 | archive-url = https://web.archive.org/web/20120423175526/http://www.rollingstone.com/culture/news/hand-to-hand-combat-20040107 | url-status = dead }}
* [http://7thavenueproject.com/post/451026680/barry-sinervo-lizards-and-evolution/ A biological example of rock paper scissors: Interview with biologist Barry Sinervo on the 7th Avenue Project Radio Show]
* [https://www.wrpsa.com The World Rock Paper Scissors Association]
* [http://www.rpscontest.com/ Rock Paper Scissors Programming Competition]
* [http://www.rockpas.com/ Rock Paper Scissors online remote edition] {{Webarchive|url=https://web.archive.org/web/20201217202012/https://rockpas.com/ |date=2020-12-17 }}
* {{cite news | url = https://www.bbc.co.uk/programmes/b0640tzr | title = Rock Paper Scissors | access-date = 2015-08-08 | last = Jenkins | first = Jolyon | publisher = [[BBC]] Radio documentary explores links between RPS and game theory }}
* [http://rock-paper-scissors.goodplace.eu Rock Paper Scissors online php implementation]
* [http://rpsls.goodplace.eu Rock Paper Scissors Lizard Spock online php implementation]

{{Hand games}}
{{Game theory}}
{{Authority control}}

[[Category:Rock paper scissors| ]]
[[Category:Children's games]]
[[Category:Games of chance]]
[[Category:Hand games]]
[[Category:Chinese games]]
[[Category:Sampling (statistics)]]
[[Category:Game theory game classes]]