Nulla poena sine lege

Latin doctrine meaning "no penalty without law"

Nulla poena sine lege is a legal formula which, in its narrow interpretation, states that one can only be punished for doing something if a penalty for this behavior is fixed in criminal law. As some laws are unwritten and laws can be interpreted broadly, it does not necessarily mean that an action will not be punished simply because a specific rule against it is not codified.

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