Common Law: What It Is and Why It Matters

Common law is a legal system that is based on precedent, which means that judges look to past court decisions to decide new cases. Common law is the basis of the legal systems in many countries, including the United States, the United Kingdom, and Canada.

How Common Law Works

When a court decides a case, it issues a written opinion that explains the reasons for its decision. This opinion is called a precedent. Precedent is binding on lower courts in the same jurisdiction, which means that lower courts must follow the precedent set by higher courts.

Over time, precedents build up to form a body of law that is known as common law. Common law is constantly evolving as courts issue new decisions that interpret and apply the law to new situations.

Advantages of Common Law

Common law has several advantages over other legal systems, including:

  • Flexibility: Common law is flexible because it can be adapted to new situations. Judges can use their discretion to interpret the law in a way that is fair and just.
  • Predictability: Common law is predictable because judges are required to follow precedent. This means that parties to a lawsuit can have a good idea of how a court is likely to rule on their case.
  • Fairness: Common law is fair because it is based on the principle of stare decisis, which means that judges must follow precedent. This helps to ensure that all parties are treated equally under the law.

Disadvantages of Common Law

Common law also has some disadvantages, including:

  • Complexity: Common law can be complex because it is based on a large body of case law. This can make it difficult for people to understand and comply with the law.
  • Expense: Common law lawsuits can be expensive because they require parties to hire lawyers and present evidence in court.
  • Slowness: Common law lawsuits can be slow because they often involve multiple levels of appeal.


Common law is a complex but flexible legal system that has been used for centuries to resolve disputes and uphold justice. Common law has both advantages and disadvantages, but it is an important part of the legal systems in many countries around the world.

Examples of Common Law

Here are a few examples of common law:

  • The principle of negligence, which is the basis for personal injury lawsuits
  • The law of contracts, which governs agreements between parties
  • The law of property, which governs ownership and use of land and other assets
  • The law of criminal procedure, which governs the rights of accused persons and the procedures that must be followed in criminal cases

Common law is a dynamic and constantly evolving body of law. New precedents are being created all the time as judges interpret and apply the law to new situations.