Legal Definitions - stare decisis

Stare decisis is a legal doctrine that means "to stand by things decided" in Latin. It is the principle that courts will follow previous court decisions when deciding similar cases. This helps to promote consistency and predictability in the legal system.

Horizontal stare decisis refers to a court following its own previous decisions. For example, if the Seventh Circuit Court of Appeals follows a ruling it made in a previous case, that is horizontal stare decisis.

Vertical stare decisis refers to a court following the decisions of higher courts. For example, if the Seventh Circuit Court of Appeals follows a ruling made by the U.S. Supreme Court, that is vertical stare decisis.

Although courts usually follow precedent, there are exceptions. If a previous decision is unworkable or badly reasoned, the court may not follow it. This is particularly true in constitutional cases. For example, in Brown v. Board of Education, the U.S. Supreme Court refused to follow the precedent set by Plessy v. Ferguson.

Suppose a court is deciding a case involving the Fourth Amendment's protection against unreasonable searches and seizures. If a previous court has already ruled on a similar case and found that the search was unreasonable, the current court will likely follow that decision. This is an example of stare decisis in action.