decisis

Decisis is most often encountered in the legal phrase stare decisis, Latin for “to stand by things decided.” In its broad sense, the term refers to the guiding principle that courts should follow established precedents when deciding new cases. This doctrine aims to promote consistency, predictability, and orderly development of the law by ensuring that similar facts yield similar legal outcomes.

In common law systems, precedents are created by court decisions and are typically binding on later cases with similar facts within the same jurisdiction. The binding element is the ratio decidendi— the legal rule or principle that formed the basis of the decision. Incidental comments, or obiter dicta, may be persuasive but are not binding. Precedents can be followed by higher or equal courts (vertical stare decisis and, to a lesser extent, horizontal adherence) and can be distinguished if the facts or legal issues differ. They may be overruled by a higher court or altered by legislation or constitutional change.

Limitations and variations exist. Some jurisdictions permit flexibility, allowing courts to reinterpret or overturn past decisions in light of new circumstances or social developments. In civil law systems, precedent plays a smaller role; statutes and codes take precedence, and court rulings guide interpretation rather than binding future outcomes. Overall, decisis describes a foundational approach in many legal systems that values settled decisions while allowing for lawful evolution.