2 The rule in subsection b is based on the idea that it is not the party that pays, but the party that often, in a professional context, provides the characteristic benefit within a contractual relationship. It is this performance that determines the type of contract you face. This relatively simple and simple approach provides legal certainty and ensures a uniform approach to determining the law applicable to a contractual relationship, regardless of the jurisdiction or arbitral tribunal to which the matter is to be decided. The choice of the law of the parties is generally confirmed by the courts of countries with developed legal systems. In particular, the Rome I Regulation provides that an explicit choice of law must be respected by the courts of all EU Member States (with the exception of Denmark).1 It follows that the introduction of an applicable law clause will allow the parties to obtain certainties: they know what right is likely to be applied to determine issues relating to their rights and obligations arising from the treaty.