by @WashULaw

Today’s phrase “common law” (Pronunciation: KOM-uhn LAW; Origin: English) refers to the legal system that was created in England and adopted in the United States, which uses previous court decisions to determine the outcome of the cases currently before the court. These previous decisions are often referred to as “legal precedent.”

Here are some example sentences that use the phrase:

“Louisiana is the only state in the U.S. that does not follow common law rules. Their state court system is based on civil law rather than common law and is often confused with the Napoleonic Code.”

“The court issued its ruling by relying on legal precedent or previous common law decisions.”

“The decisions issued in personal injury cases are governed by common law. This allows attorneys and clients to accurately predict the general outcome of a case by looking at the jury verdicts issued in previous cases.”

The use of the common law legal system in the United States hinges on the principle of stare decisis. The principle of stare decisis essentially means that cases with similar fact patterns in similar jurisdictions should be decided by the same rules, reaching a consistent result.

While many legal decisions hinge on common law principles and stare decisis, the U.S. is not a purely common law system. The U.S. relies on a combination of common law, statutory law and regulatory law, creating a comprehensive and complex legal system.

An important part of the common law system in the U.S. is the division of the courts and the application of legal precedent within the appropriate jurisdiction. The U.S. legal system is divided between the State and Federal governments. Although some states have atypical court systems, most state courts are divided into three tiers:

State or Local Courts; Appellate Courts; State Supreme Court.

The Federal court system is also divided into three tiers:

U.S. District Courts; Circuit Courts; Supreme Court.

Generally speaking, at common law, the decisions of the higher courts are binding on the lower courts in each jurisdiction but the lower courts decisions are not binding on the higher courts.

For individuals who do not come from countries that use common law, the concept can be confusing at first. Most simply put common law dictates that similar cases (in terms of both law and fact) in the same jurisdiction should reach similar conclusions.