Evolution of reward functions for reinforcement learning applied to stealth games

Abstract

Many modern games present stealth elements that allow the player to accomplish a certain objective without being spotted by enemy patrols. This gave rise to a new genre called stealth games, where covertness plays a major role. Although quite popular in modern games, stealthy behaviors has not been extensively studied. In this work, we tackle three different problems: (i) how to use a machine learning approach in order to allow the stealthy agent to learn good behaviors for any environment, (ii) create an efficient stealthy path planning method that can be coupled with our machine learning formulation, and (iii) how to use evolutionary computing in order to define specific parameters for our machine learning approach without any prior knowledge of the problem. We use Reinforcement Learning in order to learn good covert behavior capable of achieving a high success rate in random trials of a stealth game. We also propose an evolutionary approach that is capable of automatically defining a good reward function for our reinforcement learning approach.