Polybius is a fictitious 1981 arcade game that features in an urban legend.^[2] The legend describes the game as part of a government-run crowdsourced psychology experiment based in Portland, Oregon. Gameplay supposedly produced intense psychoactive and addictive effects in the player. These few publicly staged arcade machines were said to have been visited periodically by men in black for the purpose of data-mining the machines and analyzing these effects. Supposedly, all of these Polybius arcade machines then disappeared from the arcade market.

This urban legend has persisted in video game journalism and through continued interest, and it has inspired video games with the same name.

The urban legend says that in 1981, when new arcade games were uncommon, an unheard-of arcade game appeared in several suburbs of Portland, Oregon. The game was popular to the point of addiction,^[2] with lines forming around the machines and often resulting in fights over who would play next. The machines were visited by men in black, who collected unknown data from the machines,^[2] allegedly testing responses to the game's psychoactive effects. Players supposedly suffered from a series of unpleasant side effects, including seizures, amnesia, insomnia, night terrors, and hallucinations.^[3] Approximately one month after its supposed release in 1981, Polybius is said to have disappeared without a trace.^[1]

The company named in most accounts of the game is Sinneslöschen. The word is described by writer Brian Dunning as "not-quite-idiomatic German" (a word constructed outside the norms of German-language usage and grammar) meaning "sense delete" or "sensory deprivation", and in German would be pronounced [ˈzɪnəslœʃn̩]. Its meanings are derived from the German words Sinne ("senses") and löschen ("to extinguish" or "to delete"), though the way they are combined is not standard German; Sinnlöschen would be more correct.^[2]

The game has the same name as the classical Greek historian Polybius, born in Arcadia and known for his assertion that historians should never report what they cannot verify through interviews with eyewitnesses.^[4][5]

The first online mention of Polybius is a coinop.org article alleged to have been created in 1998, which extends the legend by claiming possession of a ROM image file from the 1981 arcade machine, claiming to have played it, and on May 16, 2009, promising to bring future updates pending an investigatory flight to Kyiv, Ukraine.^[1][4] The first known printed mention of Polybius, exposing the legend to a mass-market audience,^[2] is in the September 2003 issue of GamePro. The feature story "Secrets and Lies" declared the game's existence to be "inconclusive",^[6] helping to both spark curiosity and spread the story.

The alleged original Polybius arcade game is generally believed to have never existed, and the legend a hoax.^[2] Snopes.com, a fact-checking website, concludes the game is a modern-day version of 1980s rumors of "men in black". This led to the hypothesis that the government was hosting some sort of experiment and sending subliminal messages to the players.^{[7][failed verification]} Magazines and mainstream news of the early 1980s do not mention Polybius.^[8] Aside from the mockup cabinets and games inspired by the myth, no authentic cabinets or ROM dumps have ever been documented.^[4]

Skeptics and researchers differ on when, how, and why the story of Polybius began. American producer and author Brian Dunning believes it is an urban legend that grew out of a mixture of influences in the 1980s. He notes real news reports that two players fell ill in Portland on the same day in 1981, one collapsing with a migraine headache after playing Tempest,^[2] and another suffering from stomach pain after playing Asteroids for 28 hours in a filmed attempt to break a world record at the same arcade.^[9] Dunning records that the Federal Bureau of Investigation raided several video arcades in the area just ten days later, where the owners were suspected of using the machines for gambling, and the lead-up to the raid involved FBI agents monitoring arcade cabinets for evidence of tampering and recording high scores. Dunning suggests that these two events were combined into an urban legend about government-monitored arcade machines making players ill. He believes that such a myth must have been established by 1984, and that it influenced the plot of the film The Last Starfighter, in which a teenager is recruited by aliens who monitor him playing a covertly-developed arcade game. Dunning considers "Sinneslöschen" to be the kind of name that a non-German speaker would generate if they tried to create a compound word using an English-to-German dictionary.^[2]

Internet writer Patrick Kellogg believes that players claiming to remember having played or seen Polybius since the 1980s may actually be recalling the video game Cube Quest. It was released in arcades in 1983 as a shooting game played from laserdisc. Kellogg describes its visuals as "revolutionary" and far ahead of typical games of the time. He states that frequent breakdowns are typical of laserdisc games, so this one was often removed from arcades.^[10]

Ben Silverman of Yahoo! Games remarked, "Unfortunately, there is no evidence that the game ever existed, no less turned its users into babbling lunatics ... Still, Polybius has enjoyed cult-like status as a throwback to a more technologically paranoid era."^[3] Ripley's Believe It or Not! called Polybius "the most dangerous video game to never exist".^[11] Offbeat Oregon History says "There remains a possibility—a tiny one, really too small to measure — that the legend is true."^[12] Portland Monthly calls it "one of Portland's craziest urban legends", comparing it to the CIA's MKUltra mind control program of the 1950s-1970s.^[13]

In 2007, freeware developers and arcade constructors Rogue Synapse published a free downloadable game titled Polybius for Windows at sinnesloschen.com. Its design is partly based on a contested description of the Polybius arcade machine posted on a forum by an individual named Steven Roach who claimed to have worked on the original.^[14] To complete the illusion, Rogue Synapse's owner Dr. Estil Vance founded a Texas-based corporation bearing the name Sinnesloschen (without umlaut) in 2007.^[15] He transferred to it the "Rogue Synapse" trademark^[16] and a newly registered trademark on "Polybius".^[17] Its website says that it is an "attempt to recreate the Polybius game as it might have existed in 1981".^[18]

In 2016, Llamasoft announced Polybius for the PlayStation 4 with PlayStation VR support,^[19] released on the PlayStation store on Tuesday, May 9, 2017.^[20] In early marketing, its co-author Jeff Minter claimed to have been permitted to play the original Polybius arcade machine in a warehouse in Basingstoke, England.^[21] He later acknowledged that his game was inspired by the urban legend but does not attempt to reproduce its alleged gameplay.^[22]

It has a central cameo as the "main attraction" in the Nine Inch Nails music video "Less Than".^[23]

Polybius has cameos in many TV series, such as The Goldbergs (2013), The Simpsons (2006) and Dimension 404 (2017). The Loki (2021) cameo gained its own acclaim on social media, including that the game seems catastrophically integral to the multiverse, and is a key example of Loki interplaying conspiracy with reality.^[4] For Paper Girls (2022), CBR reported that the Polybius cameo conferred the series with 1980s science fiction credentials, and differentiated it from Stranger Things (2016).^[24]

The Polybius Conspiracy is a 7-part podcast published in 2017, adapted from a canceled feature film project.^[13][25]

• List of urban legends
• Satanic panic
• Toynbee tiles

• Polybius at the Killer List of Videogames, includes alleged cabinet photograph
• 7 Greatest Video Game Legends
• Polybius home page
• Article about the game in Atlas Obscura
• Eight minute documentary by the BBC