Originally from Transnational Litigation and Commercial Arbitration - 3rd Edition 

4.3.1. Introduction

As with the exercise of jurisdiction, so with the taking evidence: what goes on in a given territory is, as a starting point, subject to regulation by the sovereign, the particular State. Both in purely domestic cases and in cases involving a transnational element, where a given item of evidence is located within the forum jurisdiction concerned, that State sets the rules applicable to the taking of evidence there.

Since each sovereign State has a monopoly on the exercise of governmental power within its borders, no State may perform or authorize an act in the territory of a foreign State without the latter’s consent. So, in those cases involving evidence located in a foreign territory, the forum State’s rules might — at first blush — appear irrelevant as regards evidence-gathering within the foreign State.

In actual fact, however, the problem of taking evidence in a transnational context is considerably more complex. As with the transnational service of process,1 the solution to a given evidentiary problem at the transnational level is likely to involve a mixture of national and international rules.

4.3.2. The Taking of Evidence Under National Law 

As regards the conduct of civil trials generally, and as regards the gathering of evidence in particular, comparative observers have often drawn a distinction between the rules of procedure applicable in Common law (or at least American) jurisdictions and those applicable in (many) Civil law jurisdictions. Whereas proceedings in Common law courts are often described as “adversarial,” with the judge “umpiring” the adversarial activities of the parties’ lawyers,2 courtroom procedures in Civil law systems often seem quite different, and the distinction bears particular significance in the evidential context.