When we speak about “party autonomy” a comment on terminology is required, because the term is used in different ways. Sometimes it is used in the more limited sense of conflict of laws as the autonomy of the parties to choose the applicable law . Sometimes it is used much more generally as the autonomy of the parties to decide on all aspects of an international arbitration procedure, subject only to certain limitations of mandatory law. This chapter uses the term in this latter sense.
The principle of party autonomy is fundamental to arbitration in general and to international arbitration in particular. It is closely related to the freedom to conclude contracts and the freedom of the contractual partners to rule on the details of their relationship, which in some countries is considered to be a constitutional right of every citizen. It is also closely related to the consensual character of arbitration with the consequence that recent development of types of non-consensual arbitrations may also have an effect on party autonomy. Finally, party autonomy is fundamental to the functioning and development of private economy systems at the national level, as well as of international trade and investment.