The bots, dubbed the OpenAI Five, went up against four professional players and a DotA 2 commentator in a best-of-three series of matches. It seems that the AI were so effective that in the first game, the human players weren’t even capable of destroying one of the bot’s towers. They rallied in the second game where they managed to take down at least one tower, before moving on to the third game where the human players managed to cinch a win.
That being said, it should be noted that on the OpenAI’s website, they admitted that the game was not your standard DotA 2 game as there had to be certain modifications made to how the game was run. This meant a smaller pool of heroes to choose from, removal of certain items in the game, no summons/illusions, couriers that are invulnerable, no wards, no Roshan, and so on.
Of course it will be interesting to see how the AI would have fared had this been a “proper” DotA 2 game with all the bells and whistles, but either way it’s still a very impressive feat nonetheless. OpenAI’s efforts aren’t done yet as they are expected to take the bots to Valve’s The International DotA 2 tournament to compete against some of the world’s best teams. In the meantime if you’re interested you can check out the replay on Twitch.