OpenAI's Dota 2 Bot Defeated the MOBA's World Champions

Dota 2 is a popular multiplayer online battle arena (MOBA) game with millions of people playing it worldwide. There are currently 117 heroes (characters) in the game, which all have different movesets and therefore strengths and weakness. Due to its immense popularity and competitive nature of the game, it has huge e-sports competition with the main world championship being 'the International'. Last year, the team OG won Valve's international competition netting over $25 million in prize money and they became the world champions. OG recently got beaten by OpenAI's Dota 2 bots, the OpenAI Five, in a best of three contest. These are the same bots that lost to other Dota 2 e-sports teams last August, so this shows an incredible leap in the skill level of the bot.

In its 10 months of existence, it’s already played 45,000 years of Dota 2 gameplay. That’s a lot — it hasn’t grown bored yet.
— OpenAI founder and chairman, Greg Brockman.

Brockman also gave an insight into how the OpenAI Five has been created and said, “OpenAI Five is powered by deep reinforce learning, which means we didn’t code it how to play. We coded it how to learn". Reinforcement learning is where an AI plays the game and has no idea how what to do at all, but starts to learn due to the AI being given a reward when it does something right.

The OpenAI Five bots in action. (Source: OpenAI)

The OpenAI Five bots in action. (Source: OpenAI)

OpenAI Five currently finds the short term strategies the most attractive, which is obviously good in the short run; however, this can lead to a weakness in the long term of the game as the matches tend to last 30 to 45 minutes and even more. This means that humans are still better at deciding what is the best call in terms of long term gains rather than doing something that will mostly only help in the next five or ten minutes. MOBAs require players to collect currency in each game, which is used to buy items to make the character stronger. This means that the OpenAI Five may not be the best when it comes to knowing what item to buy that can be of a great benefit in the late game. Regardless of all of this, OpenAI Five still beat OG. This is because these short term tactics gave the bot a really good advantage early on in the game, which meant that it could continue its dominance throughout the game leading to a victory.

In the exhibition, OpenAI showed that the OpenAI Five can also play alongside human teammates and learn from their playstyle. They also announced that on April 18th at 6 pm PDT that you can play with or against the AI. You can register on their site for a chance to witness the power of the AI that crushed the souls of the elite Dota 2 players.