Legal and prescriptive theories of blame generally propose that judgments about an actor’s mental state (e.g., her knowledge or intent) should remain separate from judgments about whether the actor caused an outcome. Three experiments, however, show that, even in the absence of intent or immorality, actors who have knowledge relevant to a potential outcome will be rated more causal of that outcome than their ignorant counterparts, even when their actions were identical. Additional analysis revealed that this effect was mediated by counterfactual thinking—that is, by imagining ways the outcome could have been prevented. Specifically, when actors had knowledge, participants generated more counterfactuals about ways the outcome could have been different that the actor could control, which in turn increased causal assignment to the actor. These results are consistent with the Crediting Causality Model, but conflict with some legal and moral theories of blame.