OpenAI achieved a historic milestone in the world of artificial intelligence this weekend when its Dota 2 system, called OpenAI Five, handily bested the strategy game’s world champion e-sports team, OG, in a best-of-three contest. Now, the AI research organization wants to let the public get a taste of what it’s like to play against a program that’s virtually trained for the equivalent of 45,000 years to play the game at the highest possible level.

The company is calling the platform Arena, and it will be live for just three days starting Thursday, April 18th at 9PM ET. You can sign up here to get access, as OpenAI says it needs to allocate the proper amount of compute to handle the simultaneous play sessions for its cloud-based AI system.

OpenAI describes Arena as a “public experiment,” and it’s mostly designed to see what happens when the public is allowed to face off against its AI system outside the confines of strict tournament rules and regulations, and when you combine human abilities with those of its own AI system. “We’d known that our 1v1 bot would be exploitable through clever strategies; we don’t know to what extent the same is true of OpenAI Five, but we’re excited to invite the community to help us find out,” the company’s blog post reads.

It won’t just be a competitive contest between humans and the AI, either. OpenAI is also enabling a collaborative mode for Arena wherein combinations of human players, or just one solo human participant, can be paired with OpenAI Five bots to face off against a full five-hero roster of fellow bots. That way, OpenAI will gather some useful insight into how well its system can augment the abilities and performance of humans.

“That’s an important lesson for how the world is going to work, training these things and having them work in parallel,” OpenAI CEO Sam Altman told The Verge in an interview over the weekend. “Collaboration is one of the more positive visions we have for the future of the world — AI works alongside humans to make humans better and have more fun and more impact.”

Photo by Nick Statt / The Verge

We saw some of this collaborative play in action at the event over the weekend, with live casters playing alongside OpenAI Five and describing its weird, sometimes inexplicable behavior. OpenAI didn’t have any idea if it would work mixing both humans and bots, but it turns out the AI plays nice with its flesh and blood counterparts and can even impart some valuable knowledge.

“Note that OpenAI Five exhibits zero-shot transfer learning — it was trained to have all heroes controlled by copies of itself, but generalizes to controlling a subset of heroes, playing with or against humans. We were very surprised this worked as well as it did,” the company explains. “Our testers reported feeling supported by their bot teammates, that they learned from playing alongside these advanced systems, and that it was generally a fun experience overall.”

Now, members of the public will also get to share in some of the fun. Just don’t expect to win many games, or any at all. The version of OpenAI Five that played and won against team OG this weekend and that will be made available for Arena can beat the version of itself from last year — the same version that held its own against comparable pro teams at the 2018 International Dota 2 competition — 99.9 percent of the time.