Contracts contrary to fundamental principles and mandatory rules of European Contract Law
All the legal systems in Europe address the regulation of the so-called «illegal» or «illicit contracts», which are sanctioned with some type of invalidation. However, they deal with this issue by means of very different instruments, institutions, and legislative techniques, like the «illegal contractual cause», the contrariness to public morality (gute Sitten) or, among others, the category of «illegality» at common law. Doubtless, this disparity of approaches constitutes an important technical-juridical barrier to any attempt at harmonization of the Contract Law at a European level. However, a uniquely audacious and thought-provoking proposal for a uniform approach to illegal contracts has emerged throughout two basic instruments of soft law: the Principles of European Contract Law and the Draft Common Frame of Reference. Both regulatory texts are based on the essential distinction between contracts that are contrary to principles regarded as fundamental in the legal systems of the EU Member States, and those that infringe mandatory rules. The purpose of this paper is to analyse and describe these topics, taking into account both the instruments of soft law as well as the existing European case law.