Opinio Juris

Study Aids
Key Terms
O

Opinio Juris

Definition

The “actual practice” or customs of States. It comprises customary international law. For acts to be considered opinio juris, they must amount to a settled practice, and must also be such, or be carried out in such a way, as to be evidence of a belief that this practice is obligatory despite the lack of a rule of law requiring it.

Related rules

Mauris finibus odio eu maximus interdum. Ut ultricies suscipit justo in bibendum. Sed eu magna efficitur, luctus lorem ut, tincidunt arcu. Praesent varius sit amet erat hendrerit placerat. In posuere eget ante id facilisis. Integer semper venenatis felis lacinia malesuada.

— Interlocutory Decision on the Applicable Law: Terrorism, Conspiracy, Homicide, Perpetration, Cumulative Charging

Mauris finibus odio eu maximus interdum. Ut ultricies suscipit justo in bibendum. Sed eu magna efficitur, luctus lorem ut, tincidunt arcu. Praesent varius sit amet erat hendrerit placerat. In posuere eget ante id facilisis. Integer semper venenatis felis lacinia malesuada.

— In the Name of the Cambodian People and the United Nations and Pursuant to the Law on the Establishment of the Extraordinary Chambers in the Courts of Cambodia for the Prosecution of Crimes Committed During the Period of Democratic Kampuchea

Mauris finibus odio eu maximus interdum. Ut ultricies suscipit justo in bibendum. Sed eu magna efficitur, luctus lorem ut, tincidunt arcu. Praesent varius sit amet erat hendrerit placerat. In posuere eget ante id facilisis. Integer semper venenatis felis lacinia malesuada.

— Legality of the Threat or Use of Nuclear Weapons

Mauris finibus odio eu maximus interdum. Ut ultricies suscipit justo in bibendum. Sed eu magna efficitur, luctus lorem ut, tincidunt arcu. Praesent varius sit amet erat hendrerit placerat. In posuere eget ante id facilisis. Integer semper venenatis felis lacinia malesuada.

— Questions Relating to the Obligation to Prosecute or Extradite (Belgium v. Senegal)

Get full access FREE

With a 7-day free trial membership
Here's why 777,000 law students have relied on our key terms:
  • A complete online legal dictionary of law terms and legal definitions
  • Over 7,900 key terms written in plain English to help you not only understand the law but master it
  • The premier online law dictionary built specifically for law students
  • Easy access in class or on the go, accessible both online and through the Quimbee mobile app
  • Reliable - written by legal professors and practitioners
  • Get instant access to all related rules of law to any specific key term with a Quimbee Study Aid plan

Get full access FREE

With a 7-day free trial membership