Abstract Courts use inferences to the best explanation in many contexts and for a variety of purposes. Yet our understanding of lawyers’ uses of this inferential form is insufficient. In this article, after briefly introducing this inferential form, I set out to: (i) explain the structure of such arguments by reference to an argument scheme; (ii) clarify the types of claims courts support by deploying such inferences while attempting to justify acting in accordance with explanatory principles (inferences to the best explanation—principles, or IBE-Ps); (iii) offer an account of the ‘explanatory’ relationship on which IBE-P is predicated; (iv) explain what precisely can count as part of the explanandum in an IBE-P; and (v) discuss criteria that might be used to adjudicate which is the best among rival explanations.