Conflict of laws is a set of rules of procedural law which determine the legal system and the law of jurisdiction applying to a given legal dispute. In civil law, lawyers and legal scholars refer to conflict of laws as private international law. They typically apply when a legal dispute has a “foreign” element. In other words, Private International law or Conflict of law is a branch of interanational interstate laws and international law that controls all proceedings concerning a “foreign” law factor.
The term conflict of laws originates from situations where the ultimate outcome of a legal dispute depends upon which law applied, and the common law courts manner of resolving the conflict between those laws. However, private international law is a feature of municipal law which vary from country to country
In the United States, the existence of many states with legal rules often at variance makes the subject of conflict of laws especially urgent. In 1938, the Supreme Court ruled that each federal court must apply the conflict of laws rules of the state in which it sits. Certain provisions of the U.S. Constitution deprive the states of complete freedom to determine how they will decide cases. Article 4, Section 1 provides that, “Full Faith and Credit shall be given in each State to the Public Acts, Records, and judicial Proceedings of every other State.” The U.S. Supreme Court has interpreted this provision as requiring each state to treat as valid any judgment rendered by another state that had jurisdiction over the matter and to lend its powers of enforcement to the judgment. The sole exception is that the courts of one state do not enforce claims arising under the penal law of another.
Courts faced with a choice of law issue generally have two choices when it comes to conflict of law: A court can apply the law of the forum (lex fori)– which is usually the result when the question of what law to apply is procedural, or the court can apply the law of the site of the transaction, or occurrence that gave rise to the litigation in the first place (lex loci)– this is usually the controlling law selected when the matter is substantive.