Common Law
The common law is also called case law. The common law is the name for those legal principles created by judges in the absence of some other source of law. While the term judge-made law is currently out of favor, law created by judges is the foundation of the legal tradition in this country.
The common law tradition pre-existed the United States Constitution. In eleventh-century England, the local customs and traditions of each region of the country resulted in disparate rules of law. To facilitate the growth of trade and commerce, William the Conqueror sought to establish uniform rules of law that applied to every part of the country.
For the law to be effective in regulating and predicting conduct it needed to be consistent. The need for consistency led judges to adopt two principles that govern the common law to this day — precedent and stare decisis.
Alert
The role of the common law in the American judicial system was established in the case of Marbury v. Madison. The decision in that case created the concept of judicial review — the right of the courts to determine whether the actions of the other branches of government were permitted by the Constitution. The concept of judicial review allows the court to examine and interpret statutes and administrative regulations when necessary to resolve a legal dispute.
Precedent
Achieving consistency was not easy for eleventh-century judges.
With little statutory authority to advise them, these judges were charged with instilling predictability into the law. The task was made more difficult by the fact that the judges could not anticipate legal disputes, but could only decide disputes based on the facts before them.
Ultimately, these common-law judges settled on the concept of precedent. Simply put, the concept states that the resolution of a current dispute should be guided by a prior decision on a dispute that involved similar or identical facts. Precedent is not personal to the deciding judge; a decision by one judge serves to guide the decisions of all judges within the jurisdiction. Because judicial decisions were no longer subject to differences in regional or judicial outlook, precedent brought stability and predictability to the law.
Today, the concept of precedent underlies all legal analysis. Precedent enables the legal professional to determine the specific legal consequences that will follow from a specific set of facts. The paralegal researching a client's problem looks for cases involving similar facts. This type of case is on point because similar facts allow the prediction of a similar application of the rule of law. These predictions can be used to define the boundaries of a contract or to modify behavior that risks legal consequences.
Essential
Not all precedent is created equal. The structure of the American legal system allows each state to create and interpret its own laws without limiting the right of other states to do the same. A decision of the supreme court in one state is a mandatory precedent for all the courts in that state. It is merely a persuasive precedent for courts in another state — those courts may follow the decision, follow only part of the decision, or choose not to follow the decision at all. Precedent is only mandatory within the limits of the court's jurisdiction.
Stare decisis
Closely related to the concept of precedent is the doctrine of
The value of combining
The doctrine of
Modern Status of the Common Law
The development of the common law established many of the legal principles we rely on today. English common law evolved because there was no other source of law available, and it developed largely without the benefit of a written constitution or large body of statutory law. Today, the definition of common law relies on this history. The common law is law established by judges in the absence of any other controlling legal authority.
In recent years, both federal and state legislators have attempted to make changes in the law by enacting statutes. The proliferation of legislative enactments has had two effects on the common law.
First, some legislative enactments are designed to incorporate the common law into statute. These statutes codify the common law and become the authority relied on by the courts. Many states have codified the common law in the fields of marriage and criminal law.
Fact
State or federal statutory law is often referred to as the “code” of that jurisdiction. When legal professionals say that a legislature has “codified” the common law, they mean the principles of the common law have been enacted as statutes.
Second, when the legislature disagrees with the result reached by the common law, it may enact a statute to change that result. These statutes supplant the common law and are called statutes in derogation of the common law. Such statutes may reflect impatience with the pace of change of the common law.
Third, a legislature may enact legislation in an area of the law where there is no common-law principle. Again, these statutes are designed to speed the development of the law or to prevent the common law from expanding in a specific way. Statutes enacted in the absence of common-law principles direct the development of the law and become the controlling legal authority in that arena.

