Rückwirkungsverbot

Rückwirkungsverbot, often translated as the prohibition of retroactivity, is a legal principle that generally prevents laws from applying to events that occurred before the law was enacted. This principle is a cornerstone of legal certainty and the rule of law, ensuring that individuals and entities can rely on the existing legal framework. The core idea is that a person should not be penalized or disadvantaged by a law that did not exist at the time of their actions.

In many legal systems, particularly in German and other civil law traditions, the Rückwirkungsverbot is a fundamental constitutional right. It aims to protect legitimate expectations and prevent arbitrary changes to legal consequences. While the general principle is clear, its application can be complex. There are exceptions and nuances, especially concerning laws that are more procedural in nature or that create new rights rather than impose new burdens.

The prohibition of retroactivity is particularly important in criminal law, where it is often enshrined as a specific principle, Nullum crimen sine lege, nulla poena sine lege (no crime without law, no punishment without law). This means that an act can only be punished if it was defined as a crime by law at the time it was committed. In civil law, the Rückwirkungsverbot safeguards contractual relationships and property rights from being retroactively altered. The precise scope and interpretation of the Rückwirkungsverbot can vary between jurisdictions and are often subject to judicial review.