Legal systems value continuity. Stare decisis is the doctrine that courts should adhere to precedents established in prior decisions when deciding new cases with similar issues.

Vertical stare decisis binds lower courts to higher-court rulings; horizontal stare decisis describes a court’s practice of following its own earlier decisions. The doctrine is not absolute—courts may overrule precedent that is clearly wrong, unworkable, or outdated—but departure requires reasoned justification.

Stare decisis promotes predictability, efficiency, and legitimacy by showing that outcomes rest on principle rather than the identity of the decision-maker. Lawyers structure entire litigation strategies around the matrix of binding and persuasive authority it creates.

• Doctrine of following established precedent
• Binds lower courts to higher authority
• Allows overruling only with strong reasons
• Supports stability and equal treatment