Glossary
Stare decisis
The doctrine that courts should follow their own past decisions, and that lower courts must follow the precedent of higher courts in the same jurisdiction. Latin for "to stand by things decided."
Stare decisis is the engine of consistency in the U.S. legal system. It's why a lawyer can advise a client based on past decisions instead of guessing what each new judge will do.
The doctrine isn't absolute. Courts can overrule themselves when a past decision proves unworkable, factually wrong, or in conflict with later developments. But they're cautious: overruling precedent disrupts everyone who relied on the old rule, so courts usually need a strong reason.
Stare decisis is generally stronger for statutory interpretation (where the legislature can fix any error by amending the statute) and weaker for constitutional interpretation (where the only fix is the court itself reconsidering or a constitutional amendment).