Conflict of laws refers to a difference between the laws of two or more jurisdictions with some connection to a case, such that the outcome depends on which jurisdiction's law will be used to resolve each issue in dispute. The conflicting legal rules may come from U.S. federal law, the laws of U.S. states, or the laws of other countries.
The process by which a court determines what law to apply is sometimes referred to as "characterization" or "classification." This determination must be made in accordance with the law of the forum. A federal court in a case before it based on diversity of citizenship, for example, determines the conflict of law issue as if it were the highest court in the state in which it is sitting.
Courts faced with a choice of law issue generally have two choices:
- 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.
Federal courts play by different rules than state courts because federal jurisdiction is limited to what has been enumerated in the Constitution. The rules that federal courts must obey regarding which laws to apply are extremely complex.
[Last updated in August of 2022 by the Wex Definitions Team]
menu of sources
- Article VI - Supremacy Clause; CRS Annotated text
- Article IV, Section 1 - Full Faith and Credit Clause; CRS Annotated text
- 28 U.S.C. §§1738-1739 - State Proceedings
- 18 U.S.C. §§ 848,896,927,2345
- 47 U.S.C. § 741- Satellite and Communications Law
- 19 U.S.C. § 2504 - Trade Agreements
- 45 U.S.C. § 1213 - Railroads
Federal Judicial Decisions
- U.S. Supreme Court:
- U.S. Circuit Courts of Appeals: Recent Conflicts Decisions
State Judicial Decisions
- N.Y. Court of Appeals:
- Appellate Decisions from Other States
Conventions and Treaties
Useful Offnet (or Subscription - $) Sources
- Good Starting Point in Print: Eugene F. Scoles and Peter Hay, Hornbook on Conflict of Laws, West Group (2004)