Reinforcing Competitive Multi-Agents for Playing So Long Sucker

This paper examines the use of classical deep reinforcement learning (DRL) algorithms, DQN, DDQN, and Dueling DQN, in the strategy game So Long Sucker (SLS), a diplomacy-driven game defined by coalition-building and strategic betrayal. SLS poses unique challenges due to its blend of cooperative and adversarial dynamics, making it an ideal platform for studying multi-agent learning and game theory. The study's primary goal is to teach autonomous agents the game's rules and strategies using classical DRL methods. To support this effort, the authors developed a novel, publicly available implementation of SLS, featuring a graphical user interface (GUI) and benchmarking tools for DRL algorithms. Experimental results reveal that while considered basic by modern DRL standards, DQN, DDQN, and Dueling DQN agents achieved roughly 50% of the maximum possible game reward. This suggests a baseline understanding of the game's mechanics, with agents favoring legal moves over illegal ones. However, a significant limitation was the extensive training required, around 2000 games, for agents to reach peak performance, compared to human players who grasp the game within a few rounds. Even after prolonged training, agents occasionally made illegal moves, highlighting both the potential and limitations of these classical DRL methods in semi-complex, socially driven games. The findings establish a foundational benchmark for training agents in SLS and similar negotiation-based environments while underscoring the need for advanced or hybrid DRL approaches to improve learning efficiency and adaptability. Future research could incorporate game-theoretic strategies to enhance agent decision-making in dynamic multi-agent contexts.