Roko's basilisk is a thought experiment about the potential risks involved in developing artificial intelligence. The experiment's premise is that an all-powerful artificial intelligence from the future may retroactively punish those who did not help cause its existence; further, merely knowing about the AI incurs the risk of punishment. It resembles a futurist version of Pascal's wager, in that it suggests people should weigh possible punishment versus reward and as a result accept particular singularitarian ideas or donate money to support their development. It is named after the member of the rationalist community LessWrong who described it, though he did not originate the underlying ideas.
Despite widespread incredulity, this argument is taken quite seriously by some people, primarily some denizens of LessWrong. While neither LessWrong nor its founder Eliezer Yudkowsky advocate the basilisk as true, they do advocate for almost all of the premises that add up to it.
Roko's posited solution to this quandary is to buy a lottery ticket.