wtf is douzero?

DouZero is an AI system that learned to play DouDizhu, the most popular card game in China. DouDizhu translates roughly to "Fighting the Landlord" and is a three-player card game where two players team up as peasants against a single landlord, with everyone trying to be the first to play all their cards. The game has a very large number of possible moves on any given turn, which makes it unusually hard for AI to handle. The research behind DouZero was published at ICML 2021, a major machine learning conference. The core idea is a classic technique called Monte Carlo methods, which involves simulating many possible game sequences to estimate which moves lead to winning, combined with deep neural networks to handle the large action space. The AI trains by playing against itself repeatedly, with no human expert knowledge baked in. Starting from nothing on a single server with four GPUs, it reached top performance among hundreds of AI agents on a public leaderboard in a matter of days. The repository includes training code, pre-trained model weights, and an evaluation setup. Training requires a GPU. Evaluation can run on a CPU, including on Windows. An online demo at douzero.org lets you play against the trained AI in a browser without setting up anything locally. A Google Colab notebook is also linked so you can experiment in the cloud for free. The code is released by Kwai (the company behind the Kuaishou short-video platform) and is intended primarily as a research artifact. If you want to reproduce results or study the technique, the paper and training scripts are both available. Community members have built improved versions using different neural network architectures, and those are linked from the README as well.