Private International Law describes the body of law surrounding which law governs when there is a conflict between citizens of different countries. In common law jurisdictions, it is sometimes known as "conflict of laws."
Typically, one will be asking one or more of three questions when researching a private international law problem:
(See, e.g. David D. Siegel, A Retrospective on Babcock v. Jackson, A Personal View, 56 Alb. L. Rev. 693 (1993).)
Much private international law is governed by the domestic law of the countries in question. That is, whether or not, for example, a given foreign judgment will be enforced is a U.S. court may be governed by U.S. law. However, in recent years there has been an effort to create a more unified system of private international law, and treaties and conventions, model laws, legal guides, and other instruments may also be used. Private international law tends to be subject-specific; currently, there is no well-defined body of private international law, but certain subjects such as contracts or family law may have their own governing rules.
When researching a private international law problem, the following steps are likely to be helpful:
1. First, look at the individual jurisdictions in question to determine whether they have conflict of laws rules.
2. Find out if there is a treaty or convention governing the topic of the dispute.
3. Consult secondary sources
4. Research the law of foreign jurisdictions.