C. Hartley, Trevor Keywords: Common law | Law of contracts | International contracts | Mots clefs: Common law | Droit des obligations | Contrats internationaux | ABSTRACT In his course devoted to the Common Law approach of mandatory rules, Trevor C. Hartley, Professor at the London School of Economics and Political Science, gives several definitions of the concept of mandatory rules. He next discussed different theories that deal specifically with these rules. The author then focuses on the Rome convention and the America…