Common law refers to the section of law that is developed as results of decisions in cases, by judges. In some cases, when a decision is made by a court that will be applied to cases in the future, it is said to have set a precedent. These decisions develop into common law after a judicial opinion is created. Then, when a similar case arises in the future, the precedent set in an earlier case can be reference back to by either party. However, common law does have the ability to change over time when a newer decision counters the law presented in another. IF and when this happens, the new decision is said to have overturned the one prior. Common law is most used in civil areas of law, such as personal injury and property.