According to the story, an unheard-of new arcade game appeared in several suburbs of Portland, Oregon in 1981, something of a rarity at the time. The game, Polybius, proved to be incredibly popular, to the point of addiction, and lines formed around the machines, quickly followed by clusters of visits from men in black. Rather than the usual marketing data collected by company visitors to arcade machines, they collected some unknown data, allegedly testing responses to the psychoactive machines. The players themselves suffered from a series of unpleasant side-effects, including amnesia, insomnia, nightmares, night terrors, and even suicide in some versions of the legend. Some players stopped playing video games, while it is reported that one became an anti-gaming activist. The supposed creator of Polybius is Ed Rotberg, and the company named in the urban legend is Sinneslöschen (German for "sense-deletion"), often named as either a secret government organization or a codename for Atari. The gameplay is said to be similar to Tempest (a shoot 'em up game utilizing vector graphics), while the game is said to contain subliminal messages which would influence the action of anyone playing it.
The origin of the legend is unknown. Some internet commentators think it originated as a usenet hoax. Other bloggers believe the story is a true urban legend – one that grew out of exaggerated and distorted tales of an early release version of Tempest that caused problems with photosensitive epilepsy; the game was reported to have caused motion sickness and vertigo, and was therefore pulled.
Several people have claimed to have a ROM of the game, but none of them have made it available for public scrutiny, a "lack of hard evidence" situation typical of hoaxes and conspiracy theories. Conflicting information is even circulated regarding the style or genre of the game. Some sources claim it is a maze-style game, while others describe it as an action space-fighter.
The Polybius legend received some mass-market attention in the September 2003 issue of GamePro magazine, as part of a feature story on video game urban legends called "Secrets and Lies". The magazine determined the legend to be neither true nor false, but "inconclusive". Additionally, Snopes.com claims to have debunked the myth as a modern-day version of 1980's rumors of "Men in Black" visiting arcades and taking down the names of high scorers at arcade games.