Effects of incidental emotions on moral dilemma judgments have garnered interest because they demonstrate the context-dependent nature of moral decision-making. Six experiments (N = 727) investigated the effects of incidental happiness, sadness, and anger on responses in moral dilemmas that pit the consequences of a given action for the greater good (i.e., utilitarianism) against the consistency of that action with moral norms (i.e., deontology). Using the CNI model of moral decision-making, we further tested whether the three kinds of emotions shape moral dilemma judgments by influencing (a) sensitivity to consequences, (b) sensitivity to moral norms, or (c) general preference for inaction versus action regardless of consequences and moral norms (or some combination of the three). Incidental happiness reduced sensitivity to moral norms without affecting sensitivity to consequences or general preference for inaction versus action. Incidental sadness and incidental anger did not show any significant effects on moral dilemma judgments. The findings suggest a central role of moral norms in the contribution of emotional responses to moral dilemma judgments, requiring refinements of dominant theoretical accounts and supporting the value of formal modeling approaches in providing more nuanced insights into the determinants of moral dilemma judgments.