This research paper critically examines the doctrinal concepts of error in persona (mistake in the person) and aberratio ictus (mistake in the blow) within the framework of Indonesian substantive criminal law. While the Indonesian Criminal Code (KUHP) does not explicitly codify these Latin maxims, their underlying principles are deeply embedded in the fundamental distinction between intentional (dolus) and unintentional (culpa) acts. The paper argues that the current implicit treatment of these concepts creates a zone of legal uncertainty, forcing judges to navigate complex questions of culpability without clear statutory guidance. Through a human-centric lens, this research moves beyond dogmatic analysis to explore the real-world implications for victims, perpetrators, and the integrity of justice. Utilizing a normative juridical methodology supplemented by comparative legal analysis (drawing on the Netherlands, Germany, Italy, Spain, and the Philippines), the paper highlights how clarifying these concepts is not merely an academic exercise but a necessary step toward fulfilling the law’s core objectives: justice, legal certainty, and fairness. The conclusion posits that explicit recognition or systematic jurisprudential development of error in persona and aberratio ictus would strengthen Indonesia’s criminal justice system by providing a more nuanced and just framework for assessing moral blameworthiness in an imperfect world.