Rule-based Reasoners in Epistemic Logic Anthia Solaki Abstract: In this paper, we offer a balanced response to the problem of logical omniscience, whereby agents are modeled as non-omniscient yet still logically competent reasoners. To achieve this, we account for the deductive steps that form the epistemic state of an agent. In particular, we introduce operators for applications of inference rules and design a possible-worlds model which is (a) equipped with a syntactic valuation, determining the agent's (explicit) knowledge, and (b) suitably structured by rule-induced transitions between worlds. As a result, we obtain a detailed analysis of the agent's reasoning processes. We then offer validities that exemplify how the problem of logical omniscience is avoided and compare our response to others in the literature. A sound and complete axiomatization is also provided. We fi�nally show how simple extensions of this setting make it compatible with tools from Dynamic Epistemic Logic (DEL) and open to the incorporation of empirical �findings on human reasoning.