Other legal and political systems are very different from the US system, which came from English common-law traditions and the framers of the US Constitution. Our legal and political traditions are different both in what kinds of laws we make and honor and in how disputes are resolved in court.
The common-law tradition is unique to England, the United States, and former colonies of the British Empire. Although there are differences among common-law systems (e.g., most nations do not permit their judiciaries to declare legislative acts unconstitutional; some nations use the jury less frequently), all of them recognize the use of precedent in judicial cases, and none of them relies on the comprehensive, legislative codes that are prevalent in civil-law systems.
The main alternative to the common-law legal system was developed in Europe and is based in Roman and Napoleonic law. A civil-law or code-law system is one where all the legal rules are in one or more comprehensive legislative enactments. During Napoleon’s reign, a comprehensive book of laws—a code—was developed for all of France. The code covered criminal law, criminal procedure, noncriminal law and procedure, and commercial law. The rules of the code are still used today in France and in other continental European legal systems. The code is used to resolve particular cases, usually by judges without a jury. Moreover, the judges are not required to follow the decisions of other courts in similar cases. As George Cameron of the University of Michigan has noted, “The law is in the code, not in the cases.” He goes on to note, “Where several cases all have interpreted a provision in a particular way, the French courts may feel bound to reach the same result in future cases, under the doctrine of jurisprudence constante. The major agency for growth and change, however, is the legislature, not the courts.”
Civil-law systems are used throughout Europe as well as in Central and South America. Some nations in Asia and Africa have also adopted codes based on European civil law. Germany, Holland, Spain, France, and Portugal all had colonies outside of Europe, and many of these colonies adopted the legal practices that were imposed on them by colonial rule, much like the original thirteen states of the United States, which adopted English common-law practices.
One source of possible confusion at this point is that we have already referred to US civil law in contrast to criminal law. But the European civil law covers both civil and criminal law.
There are also legal systems that differ significantly from the common-law and civil-law systems. The communist and socialist legal systems that remain (e.g., in Cuba and North Korea) operate on very different assumptions than those of either English common law or European civil law. Islamic and other religion-based systems of law bring different values and assumptions to social and commercial relations. For the Islamic and Middle Eastern law, see http://www.soas.ac.uk/library/subjects/law/region/islamic.
Legal systems vary widely in their aims and in the way they process civil and criminal cases. Common-law systems use juries, have one judge, and adhere to precedent. Civil-law systems decide cases without a jury, often use three judges, and often render shorter opinions without reference to previously decided cases.