The Dialectic Between the Principle of Legality and Legal Pluralism in The National Criminal Code

The Indonesian national Criminal Code, in force since 2 January 2026, recognises the living law as a basis for determining that a person deserves punishment even where the act is not regulated in the Code. Article 2 stands in tension with the principle of legality in Article 1(1), which demands legal certainty through written, clear, and non-retroactive rules. This article analyses the concept and regulation of living law in the national Criminal Code, the dialectic between legality and living law and its implications for legal certainty, and the form of legal pluralism it embodies together with the challenges of implementation. It is a normative legal study using statutory and conceptual approaches. The findings show that the tension is not eliminated but bridged by the conditions in Article 2(2) and Government Regulation No. 55 of 2025, which require customary offences to be established in regional regulations. This restores part of the legal certainty, but makes the pluralism in the Code state-controlled and leaves issues such as wording that may open the door to analogy, dual enforcement, and human rights protection.