Impact of Precedent—The Principle of Stare Decisis
The defining principle of common law is the requirement that courts follow decisions of higher level courts within the same jurisdiction. It is from this legacy of stare decisis that a somewhat predictable, consistent body of law has emerged.
- See more at: http://www.lexisnexis.com/en-us/lawschool/pre-law/intro-to-american-legal-system.page#sthash.lRh3NM0V.dpuf