In common law legal systems, a precedent or authority is a legal case establishing a principle or rule that a court or other judicial body adopts when deciding subsequent cases with similar issues or facts.

Description

The precedent on an issue is the collective body of judicially announced principles that a court should consider when interpreting the law. When a precedent establishes an important legal principle, or represents new or changed law on a particular issue, that precedent is often known as a landmark decision.

Precedent is central to legal analysis and rulings in countries that follow common law like the United Kingdom and Canada (except Quebec). In some systems precedent is not binding but is taken into account by the courts.

Binding precedent

main: Binding precedent

Precedent that must be applied or followed is known as binding precedent (alternately mandatory precedent, mandatory or binding authority, etc.). Under the doctrine of stare decisis, a lower court must honor findings of law made by a higher court that is within the appeals path of cases the court hears. In the United States state and federal courts, jurisdiction is often divided geographically among local trial courts, several of which fall under the territory of a regional appeals court, and all regional courts fall under a supreme court. By definition decisions of lower courts are not binding on each other or any courts higher in the system, nor are appeals court decisions binding on each other or on local courts that fall under a different appeals court. Further, courts must follow their own proclamations of law made earlier on other cases, and honor rulings made by other courts in disputes among the parties before them pertaining to the same pattern of facts or events, unless they have a strong reason to change these rulings.

One law professor has described mandatory precedent as follows:

Given a determination as to the governing jurisdiction, a court is "bound" to follow a precedent of that jurisdiction only if it is directly in point. In the strongest sense, "directly in point" means that: (1) the question resolved in the precedent case is the same as the question to be resolved in the pending case, (2) resolution of that question was necessary to disposition of the precedent case; (3) the significant facts of the precedent case are also present in the pending case, and (4) no additional facts appear in the pending case that might be treated as significant.

In extraordinary circumstances a higher court may overturn or overrule mandatory precedent, but will often attempt to distinguish the precedent before overturning it, thereby limiting the scope of the precedent in any event.