Case law, also known as common law, are rules of law derived from judicial decisions in particular court cases. Higher court decisions are binding on lower courts based on the concept of precedent, or stare decisis, which means to follow or adhere to what was previously decided.
Case law is the lowest level of legal authority, since the role of the judiciary is to simply interpret existing laws, not make new ones. However, judicial decisions typically elaborate on these laws in a way that, in practice, often do create new laws.
The actual hierarchy of legal authority in the United States is as follows:
- Administrative Regulations (carry the same weight as statutes)
- Case law (court opinions)
It is important to note that this hierarchy exists at both the federal and state levels. The federal government has exclusive authority over certain types of legal subject matters, copyright law being just one of many examples. States create their own constitutions, laws, regulations and case law for all other subject matters that federal law does not control.
There are many complexities involved in the determination as to whether or not a legal matter falls under federal or state jurisdiction that go beyond the scope of this article.
The most important thing to know when conducting case law research is that for legal matters relating to federal law, federal case law applies, and for legal matters relating to state law, state case law applies.
The hierarchy of authority in state courts is as follows:
- Court of Last Resort – highest court usually called the Supreme Court in most states.
- Appellate Court – hears appeals from parties that lost at the trial court level.
- Trial Court – the first level court where the legal action was initially brought.
Some state courts may have other names for their court levels. For example, in the state of New York, the lowest level court is called the Supreme Court, and the highest level court is called the Court of Appeals.
The federal court system is three-tiered as follows:
- The Supreme Court of the United States – the highest court in the country.
- Circuit Court of Appeals – hears appeals from parties that lost at the lower court level.
- District Court – the first level court where the legal action was initially brought.
For more information, read our blog article “Deciphering the Lawyer Code: What Case Citations Mean”, or watch this video to learn how to conduct legal research for free using Google Scholar.
The information on this website is intended as general legal information only and should not form the basis of legal advice of any kind. Individuals seeking specific legal advice should consult a lawyer.