The principle of lex stricta is of paramount importance as it restricts judicial arbitrariness. Criminal norms should be interpreted within the margins of the wording of the text. The purpose of this is to bind judicial interpretation to the wording of the statute. This is meant to subject the courts to the superiority of the legislature: the legislature – and not the courts – is the one that expresses through its statutes the values to be protected and the scope of their protection.
Naturally, the principle is addressed solely to the courts and obliges them to deduce the scope of criminalisation solely from the wording of the text, which marks the limits of criminalisation.
As the examination of the wording of a statute is very important, the lex stricta principle aims at safeguarding a strict interpretation, through the prohibition of certain methodologies that allow courts to import their own views.
Similarly in common law, the presumption of strict construction applies only after all other methods are used and the statute still remains unclear. A strict construction means that where there is ambiguity, the most favourable – for the accused – interpretation should be adopted.
(The Principle of Legality in European criminal law, Intersentia, decembrie 2015, la la pp. 90-1)