The French have what is called a civil law system. This means that their law is based code or the interpretation of laws (or statutes). The only state in the United States that has a civil law system is Louisiana. All the remaining states follow a common law system. Common law means that a court will look at prior rulings of appellate courts and make decisions based on how those prior cases were interpreted. So the closer the facts of a current case look like a case previously decided, then the more likely a court will follow that decision. This means U.S. courts use a system of what is called precedent to decide a case.