Friday November 12 11:35 – Friday November 12 12:10 in Planck Bohr

MimicBot: Combining Imitation and Reinforcement Learning to win the Bot Bowl competition

Nicola Pezzotti

Prior knowledge:
No previous knowledge expected


In this talk, I will introduce you to MimicBot, a reinforcement learning agent that uses imitation learning to play Blood Bowl. MimicBot won the Bot Bowl III competition and it is the first machine learning model to beat a scripted AI agent.



This paper describe an hybrid agent trained to play in Fantasy Football AI which participated in the Bot Bowl III competition. The agent, MimicBot, is implemented using a specifically designed deep policy network and trained using a combination of imitation and reinforcement learning. Previous attempts in using a reinforcement learning approach in such context failed for a number of reasons, e.g. due to the intrinsic randomness in the environment and the large and uneven number of actions available, with a curriculum learning approach failing to consistently beat a randomly paying agent. Currently no machine learning approach can beat a scripted bot which makes use of the domain knowledge on the game. Our solution, thanks to an imitation learning and a hybrid decision-making process, consistently beat such scripted agents. Moreover we shed lights on how to more efficiently train in a reinforcement learning setting while drastically increasing sample efficiency. MimicBot is the winner of the Bot Bowl III competition, and it is currently the state-of-the-art solution.