Thorough Examination of the Lex Favor Reo Principle: Dynamics of Transitory Law from the Old Criminal Code to the National Criminal Code

20 Dec 2025 04:32 WIB 20 December 2025 04:32 WIB 5 minutes reading time: 5 minutes 26 read

Updated: 17 Jan 2026 19:15 WIB 17 January 2026 19:15 WIB

In-depth analysis of the Lex Favor Reo principle in criminal law. Understanding the application of the most favorable legal principle in the transition of the New Criminal Code.

Ilustrasi Gambar oleh Redaksi (Source: AI Generate)

Table of Contents

Basic Philosophy: Between Sword and Scales
Normative Foundation: Transformation from WvS to the National Criminal Code
1. Old Criminal Code Regime (Wetboek van Strafrecht)
2. New Criminal Code Regime (Law No. 1 of 2023)
Classic Debate: Formal vs. Material Theory
Parameters for Determining "The Most Advantageous"
Constitutional Dimension: The Role of the Constitutional Court
Conclusion

Section 2/3: Normative Foundation: Transformation from WvS to the National Criminal Code

Normative Foundation: Transformation from WvS to the National Criminal Code

The existence of the principle of Lex Favor Reo in Indonesia has strong roots and has experienced significant strengthening in the new criminal law regime.

1. Old Criminal Code Regime (Wetboek van Strafrecht)

In the colonial-era Criminal Code, this principle is regulated in Article 1 paragraph (2):

"If there is a change in legislation after the act is committed, then the provision most favorable to the defendant shall be applied."

This article has been a guideline for decades, but it often sparks debate regarding the limits of "changes in legislation" and the parameters of "favorable".

2. New Criminal Code Regime (Law No. 1 of 2023)

Law Number 1 of 2023 concerning the Criminal Code (New Criminal Code) provides a more comprehensive and detailed regulation in Article 3.

Not only does it affirm the same principle, but the New Criminal Code explicitly regulates the technical consequences if decriminalization occurs. Article 3 paragraphs (2) to (4) affirm that if an act is no longer considered a criminal act according to the new law, then the legal process must be stopped, and if it has already been decided, the convicted person must be released. This provides far more rigid legal certainty than the previous regime.