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Pluribus

Pluribus is a computer poker player and artificial intelligence system developed by Facebook AI Research and Carnegie Mellon University.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 26, 2026|2 min read| Fact-checked

Pluribus is a computer poker player and artificial intelligence system developed by Facebook AI Research and Carnegie Mellon University. It became known in 2019 for defeating elite human professionals in six-player no-limit Texas hold'em, a major milestone in multiplayer imperfect-information games.

Background

Pluribus was developed as a research system to test whether AI could outperform humans in multiplayer poker, where players must act with incomplete information. It followed earlier work on heads-up poker bots such as Libratus.

Development and method

The project was led by researchers at Facebook AI Research and Carnegie Mellon University. Reports described training through extensive self-play and the use of counterfactual regret minimization and search to choose actions.

Performance against professionals

Researchers reported that Pluribus beat top human professionals in six-player no-limit Texas hold'em, including games with one bot against five humans and five bots against one human. The results were published in Science in 2019.

Significance

Pluribus was widely described as a breakthrough because multiplayer poker is more complex than one-on-one play and involves bluffing and hidden information. The work was framed as a proof of concept for broader AI research rather than a commercial product.

Key facts

  • Pluribus is an AI poker bot built by researchers from Facebook and Carnegie Mellon University.
  • It was designed for six-player no-limit Texas hold'em, a multiplayer version of poker with hidden information.
  • In 2019, researchers reported that Pluribus defeated elite professional poker players over 10,000 hands.
  • The system was presented as the first bot to beat humans in a complex multiplayer competition.
  • The bot's success was described as a milestone in AI research on imperfect-information games.
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Canadian context

Pluribus has indirect relevance to Canadian readers through its contribution to global AI research and to computer science work on imperfect-information games, an area of interest to researchers and industry in Canada.

Frequently asked questions

What is Pluribus?
Pluribus is an artificial intelligence poker bot developed by Facebook AI Research and Carnegie Mellon University.
What game did Pluribus play?
It played six-player no-limit Texas hold'em poker.
Why was Pluribus important?
It was reported to be the first AI bot to beat elite humans in a complex multiplayer poker setting.
Who developed Pluribus?
The project was developed by researchers including Noam Brown and Tuomas Sandholm.
When was Pluribus reported?
Its results were published and widely reported in 2019.
Was Pluribus a commercial product?
Available reporting described it as a research system and proof of concept rather than a commercial product.

References

  1. Wikipediahttps://en.wikipedia.org/wiki/Pluribus_(poker_bot)
    Supports: Basic identification of Pluribus as an AI poker bot, its developers, game format, and 2019 release.
  2. BBC Newshttps://www.bbc.com/news/technology-48959931
    Supports: Describes Pluribus as a superhuman poker-playing AI and notes its ability to beat world-leading professionals.
  3. Sciencehttps://www.science.org/doi/10.1126/science.aay2400
    Supports: Primary research article reporting Pluribus's performance in six-player no-limit Texas hold'em and its significance.
  4. Engadgethttps://www.engadget.com/2019-07-11-facebook-and-cmus-poker-ai-beat-fives-pros-at-once.html
    Supports: Reports that Pluribus beat multiple professional players simultaneously and describes it as a milestone.
  5. Wiredhttps://www.wired.com/story/new-poker-bot-beat-multiple-pros/
    Supports: Explains the research context, method, and significance of Pluribus as a proof of concept.
  6. ResearchGatehttps://www.researchgate.net/publication/334466645_Superhuman_AI_for_multiplayer_poker
    Supports: Contains metadata and excerpts of the Science paper describing Pluribus's training and results.