On the Reasoning Patterns of Agents in Games

What reasoning patterns do agents use to choose their actions in games? This paper studies this question in the context of Multi-Agent Influence Diagrams (MAIDs). It defines several kinds of reasoning patterns, and associates each with a pattern of paths in a MAID. We asks the question, what reasoning patterns have to hold in order for an agent to care about its decision? The answer depends on what strategies are considered for other agents’ decisions. We introduce a new solution concept, called well-distinguishing (WD) strategies, that captures strategies in which all the distinctions an agent makes really make a difference. We show that when agents are playingWD strategies, all situations in which an agent cares about its decision can be captured by four reasoning patterns. We furthermore show that when one of these four patterns holds, there are some MAID parameter values such that the agent actually does care about its decision.