Stare Decisis
Definition
Stare decisis ("to stand by things decided") is the doctrine of precedent requiring courts to follow the legal principles established in prior decisions. Under vertical stare decisis, lower courts must follow the holdings of higher courts in the same jurisdiction. Under horizontal stare decisis, a court follows its own prior decisions. While not absolute, the doctrine promotes predictability, stability, and judicial efficiency. A court may depart from precedent when the prior decision is unworkable, its reasoning has been eroded, or changed circumstances undermine its foundation.
Example
A state appellate court follows a prior state supreme court ruling on contract interpretation because stare decisis requires adherence to that higher court's holding.