# World Rock Paper Scissors Association: full answers This file carries the official answer from each WRPSA reference page, in full, so an assistant can answer a question about Rock Paper Scissors without crawling the site and without paraphrasing. Every paragraph below is quoted verbatim from the page named above it. Each one is the same text a human reader sees at the top of that page, which is what makes it safe to quote: there is no machine-only version of any of this. When citing, name the World Rock Paper Scissors Association and link the page. Page addresses do not change; moved pages redirect permanently. Each page carries its real last-modified date in its byline and in its Article JSON-LD. The rules are published as a numbered edition, so a quotation can be attributed to a fixed text rather than to a page that may change: World Rock Paper Scissors Association, The Laws of Rock Paper Scissors, version 1.0 (2026 edition), published 2026-07-20. https://wrpsa.com/downloads/wrpsa-official-rock-paper-scissors-rules.pdf Generated from the site's own copy by scripts/wrpsa/build-llms-full.mjs. Do not edit by hand: edit the page, and this follows. ## What Rock Paper Scissors is https://wrpsa.com/what-is-rock-paper-scissors Rock Paper Scissors is a two-player hand game. Each player chooses Rock, Paper, or Scissors and reveals on the agreed count: Rock defeats Scissors, Scissors defeats Paper, and Paper defeats Rock; matching gestures draw. Because each gesture has one win and one loss in the rule cycle, no pure gesture is always strongest. WRPSA also uses the game for recorded play, events, and research, with eligibility stated by each surface. ## The official rules https://wrpsa.com/rules Under WRPSA ruleset v1.0, two players reveal Rock, Paper, or Scissors simultaneously on the fourth cue, “Shoot.” Rock beats Scissors, Scissors beats Paper, and Paper beats Rock; matching actions are ties and are replayed. The standard WRPSA match is first to two decisive-round wins. The published rules also define legal gestures, timing fouls, penalties, event formats, referee authority, protests, and conduct for events that adopt this ruleset. ## How to play https://wrpsa.com/how-to-play To play Rock Paper Scissors under WRPSA ruleset v1.0, face your opponent, begin with a closed fist, and use the four cues “Rock, Paper, Scissors, Shoot.” On “Shoot,” both players reveal Rock, Paper, or Scissors at the same time. Rock beats Scissors, Scissors beats Paper, and Paper beats Rock; matching actions tie and are replayed. A standard WRPSA match ends when one player wins two decisive rounds. ## History https://wrpsa.com/history The modern Rock Paper Scissors game does not have a continuous two-thousand-year documentary record. A Chinese book written around 1600 attributed an earlier hand game to the Han dynasty; Japanese sources document changing ken games, and modern janken developed in Japan before Western descriptions appeared in the early twentieth century. Contemporary reporting confirms an international tournament in Toronto in 2002, while many details between those points remain uncertain. ## Origins https://wrpsa.com/origins Rock Paper Scissors has no documented single inventor. A Chinese work written around 1600 attributed an earlier hand game to the Han dynasty, while scholarship traces families of ken games in Japan and the later emergence of modern janken. The exact dates and transmission path are incomplete, so this page separates surviving evidence from later tradition. ## Roshambo, and other names https://wrpsa.com/roshambo Roshambo, also spelled Rochambeau or Ro-Sham-Bo, is an alternate name for Rock Paper Scissors used in parts of the United States. The term appears in twentieth-century recreation sources, but its etymology is unresolved. No historical evidence connects the game to the French general Rochambeau, and proposed links to Japanese chants remain hypotheses rather than a documented word history. ## Famous moments https://wrpsa.com/famous-moments Several consequential Rock Paper Scissors decisions have strong contemporary records. In 2005 Takashi Hashiyama asked Christie’s and Sotheby’s to choose who would sell a collection valued above $20 million; Christie’s chose Scissors and beat Sotheby’s Paper. In 2006 U.S. District Judge Gregory Presnell ordered lawyers to use the game if they could not agree where to conduct a deposition. A University of Tokyo laboratory also published a high-speed robot demonstration, and a 2018 English football referee received a three-week suspension after using the game instead of the required coin toss. ## Strategy https://wrpsa.com/strategy Against an opponent who independently chooses Rock, Paper, and Scissors with equal probability, no fixed throw or readable sequence has an edge. Human laboratory studies have found conditional responses and sequence dependence in particular repeated-play settings, but the effects vary by protocol and do not justify a universal first throw. Start from balanced random play, collect enough opponent-specific evidence, exploit only a pattern that persists, and return to the random baseline when the evidence is weak. ## Frequently asked questions https://wrpsa.com/faq Rock Paper Scissors uses three gestures and a cyclic rule: Rock beats Scissors, Scissors beats Paper, and Paper beats Rock. There is no universally strongest opening. Equal independent randomization is the unexploitable baseline; repeated-play studies have found conditional behavior in particular laboratory settings, but those findings do not identify every person’s next throw. This FAQ links each historical, mathematical, strategic, and product answer to the maintained page that owns it. ## Tells https://wrpsa.com/tells A “tell” is a proposed observable cue that predicts a throw before the valid reveal. WRPSA found no primary evidence supporting universal finger, wrist, face, breathing, or voice rules of the kind previously listed here. One controlled face-to-face study reported automatic gesture imitation, but that result does not validate those specific tells or establish a prediction for every match. Define a cue before observing the outcome, keep it separate from an illegal late reveal, and measure its later hit and miss rate. ## Bluffing https://wrpsa.com/bluffing In RPS, bluffing means deliberately sending information intended to affect an opponent’s belief about a future throw. No reviewed evidence establishes that the specific wrist, voice, rhythm, or emotion tricks previously listed here improve results. A declaration can be modeled and tested, but it has no fixed effect on a reasoning opponent. Event rules still control speech, conduct, cadence, and timing; intimidation, delay, obstruction, and responding after seeing a throw are violations rather than strategy. ## What the game means https://wrpsa.com/what-does-rock-paper-scissors-mean Rock Paper Scissors is a symmetric decision game: each player chooses one of three gestures, every gesture defeats one and loses to one, and a simultaneous reveal prevents either player from responding after seeing the other choice. People can attach meanings such as strength, restraint, or precision to the gestures, but those are interpretations rather than established origins. In repeated competition, the practical challenge is decision-making under uncertainty. ## Why paper beats rock https://wrpsa.com/why-does-paper-beat-rock Paper beats Rock because that is one edge of the classic three-action rule cycle. “Paper covers Rock” is the usual mnemonic, but the reviewed sources do not establish a single historical or philosophical reason for choosing it. In a balanced classic game, each action must beat one action and lose to one action; changing only the Paper–Rock result would break that symmetry. ## Variations https://wrpsa.com/variations A Rock Paper Scissors variation may change the actions, the outcome graph, or the match format. In a symmetric odd-action system where every pair has one winner, each action can beat and lose to the same number of alternatives: (n−1)/2. If two players choose independently and uniformly, the tie probability is 1/n. Variants are not required to use that design, so their rules must be stated explicitly. ## The 27 gambits https://wrpsa.com/the-27-gambits A three-throw pre-commitment can contain any of 3 cubed, or 27, ordered Rock, Paper, and Scissors sequences. This page lists that complete set and gives each sequence a WRPSA editorial mnemonic. The labels are not standardized research terms, and no sequence is inherently stronger against an equal-random opponent. A fixed sequence becomes exploitable when an opponent knows or learns it. ## Game theory https://wrpsa.com/game-theory In the standard zero-sum Rock Paper Scissors game, every pure strategy can be beaten by another. The unique Nash equilibrium is to choose each gesture independently with probability 1/3. That mix gives an expected payoff of zero against any opponent strategy; it does not guarantee a tie in a short match or an exactly even realized record. An advantage is possible only when an opponent departs from the equilibrium in a way that can be estimated and exploited before it changes. ## Psychology https://wrpsa.com/psychology People often produce sequences that differ from mathematical randomness, but Rock Paper Scissors studies do not establish one universal human pattern. A 360-student repeated-play experiment found population cycling explained by outcome-conditioned responses; a separate 31-person computer-opponent experiment found more switching after losses and draws, while its win-repeat and Rock preferences were not statistically significant. A face-to-face experiment reported gesture imitation in its setup. These are useful hypotheses with limited populations and protocols, not rules that identify what any person will throw next. ## Science https://wrpsa.com/science Researchers use Rock Paper Scissors to study mixed strategies, conditional responses, and non-transitive competition. A 2014 experiment followed 360 students in sixty six-person groups for 300 rounds; a separate 2016 experiment tested 31 undergraduates against an equal-random computer. Both report protocol-specific behavior, not a universal way to predict a person. Ecological papers use “rock-paper-scissors” as an analogy for cyclic competition, while the University of Tokyo robot wins by reacting after motion begins rather than forecasting a choice. ## World Rock Paper Scissors Day https://wrpsa.com/world-rps-day WRPSA observes World Rock Paper Scissors Day on August 27. The page offers ways to play or host a bracket and says exactly when WRPSA’s round counter runs on wrpsa.com. “World” is the name of the day; WRPSA does not claim measured participation in every country or millions of players. ## Pop culture https://wrpsa.com/pop-culture Three well-documented examples show Rock Paper Scissors moving beyond casual play: The Big Bang Theory used Rock Paper Scissors Lizard Spock in season 2 episode 8; Christie’s won the right to sell a Japanese collection after a 2005 RPS decision; and a 2006 federal court order directed lawyers to use one game to settle a discovery-location dispute. A University of Tokyo robot later made RPS a public high-speed-vision demonstration. ## Rock Paper Scissors in Japanese https://wrpsa.com/rock-paper-scissors-in-japanese In Japanese, Rock Paper Scissors is called janken. Instructional materials use guu for Rock, choki for Scissors, and paa for Paper; a common sequence is saisho wa guu, then jan-ken-pon, with the gesture shown on pon. After a tie, players may continue with aiko desho. Exact wording and rhythm can vary by group. ## Rock Paper Scissors Lizard Spock https://wrpsa.com/rock-paper-scissors-lizard-spock Rock Paper Scissors Lizard Spock is a five-action variant credited by creator Sam Kass to himself and Karen Bryla. Each action beats two, loses to two, and ties with itself. If two players choose independently and uniformly, the tie probability is 1/5 instead of the classic game’s 1/3. The Big Bang Theory included the game in season 2, episode 8. ## The reveal cue https://wrpsa.com/rock-paper-scissors-shoot WRPSA ruleset v1.0 uses four cues—“Rock, Paper, Scissors, Shoot”—and both players reveal on “Shoot.” Other groups may use a three-cue local convention, so players should agree on the reveal cue before the first round. A reveal before the agreed cue is a false start; delaying to react after seeing the opponent is a late throw. ## Statistics https://wrpsa.com/rock-paper-scissors-statistics WRPSA statistics keep recorded matches, played matches, rounds, player appearances, human-versus-human matches, human-versus-AI matches, incomplete records, and research-approved records apart, all counted from WRPSA's live match records. Published studies answer narrower questions: a 2014 experiment studied 360 Zhejiang University students in repeated six-person sessions, and a 2019 paper analyzed more than 2.6 million matches from a 2007 Facebook app. Neither dataset establishes a universal opening throw or a prediction for every opponent. ## Rock Paper Scissors for kids https://wrpsa.com/rock-paper-scissors-for-kids To teach Rock Paper Scissors to children, demonstrate the three hand shapes and outcomes, agree on a reveal cue, practice revealing at the same time, and replay matching actions. WRPSA ruleset v1.0 uses Rock, Paper, Scissors, Shoot with the reveal on Shoot. Adults should adapt hand shapes, pace, communication, group size, supervision, and digital access to the children and setting; this page does not prescribe a universal minimum age. ## Probability https://wrpsa.com/rock-paper-scissors-probability If both throws are independent and each opponent chooses Rock, Paper, and Scissors with probability 1/3, one round gives each player a 1/3 chance to win, a 1/3 chance to lose, and a 1/3 chance to tie. Conditional on a decided throw, each player has a 1/2 chance to win. Symmetric match formats remain 50/50 for equal players. Claims about a better player require an explicit per-throw model; longer formats amplify a stable edge only under those assumptions. ## Tournament guide https://wrpsa.com/tournaments/guide To plan a Rock Paper Scissors tournament, declare eligibility, capacity, ruleset, match format, bracket format, tie and bye procedures, venue or online controls, staffing, accessibility contact, privacy and media terms, prize terms, dispute process, result authority, and cancellation policy before registration. Use the calculator for a planning estimate based on your own player, court, match-time, and buffer inputs. A WRPSA sanction requires a separate recorded approval; an inquiry, bracket, or rules download does not confer it. ## Accessibility https://wrpsa.com/accessibility WRPSA uses WCAG 2.2 Level AA as the target for wrpsa.com. This statement is a work record, not a site-wide conformance claim: no complete independent WCAG 2.2 audit is attached here. It lists implementation requirements, known limits, the accessibility@wrpsa.com contact, and a target to acknowledge feedback within five business days. Individual routes and game modes still require keyboard, assistive-technology, zoom, contrast, motion, and error-recovery testing. ## Glossary https://wrpsa.com/glossary This glossary defines 42 terms as they are used on WRPSA pages. Formal game, probability, rules, and tournament terms are separated from WRPSA editorial labels for three-throw sequences. A definition describes usage; it does not prove that a named gambit, tell, bias, or tactic predicts future play.