How Does Doctrine of Precedent Work?

The legal doctrine of precedent is used when a court system decides a case based on a previous case with similar circumstances. Preceding cases should persuade current jurisprudence to act in a similar fashion, according to USLegal. Precedent allows for stability and predictability in legal systems, and it follows the norms and mores of the community in which the court serves.

Cornell University Law School calls the doctrine of precedent "stare decisis," or "to stand by things decided." American courts cite this Latin term when invoking precedents in cases pertaining to similar issues that have already been decided. In general, courts side with the preceding case law, but not always.

One prevalent example of American courts following precedent involves Roe v. Wade. In the 1992 case Planned Parenthood of Southeastern Pennsylvania v. Casey, the U.S. Supreme Court cited stare decisis dozens of times when it handed down decisions regarding five abortion laws in Pennsylvania on the books since 1982, according to Cornell University Law School.

Australian law cites examples of cases wherein high-level courts reversed previous decisions, even under similar circumstances. A controversial 2008 case, Imbree v. McNeilly, overturned a 1986 case regarding a learning driver's responsibility for a passenger's injury, according to associate law professor Matthew Harding from The University of Melbourne. Originally, Australian courts ruled that a learning driver is responsible for another person's injuries if the driver is negligent. In 2008, that decision was reversed.