A court decision is the written ruling made by a judge in a case. Judges use the law gathered from previous cases (called precedent) to decide new disputes. A judge may also create a new rule or principle based on the facts of a case. Case law can be either constitutional or statutory.
A Supreme Court decision usually consists of several opinions. The first opinion is called the majority opinion. The majority opinion states the outcome of the case and explains how the Court reached that conclusion. Justices who agree with the majority opinion but wish to add further comments or clarification to the majority opinion write a concurring opinion. Justices who disagree with the outcome or the reasoning of the majority opinion write a dissenting opinion. Justices who write dissenting opinions help shape future legal arguments by providing an alternative viewpoint to the majority’s. Justice John Marshall Harlan authored more than 120 dissents during his tenure on the Court, and is known as one of the great dissenters for his fiery dissent in Plessy v. Ferguson, in which he argued against the “separate but equal” principle behind racial segregation.
The Supreme Court only hears a case on appeal if it has already been decided by a lower court, such as a federal district court or a state supreme court. Generally, only a small number of cases are accepted for review by the Supreme Court each year.
Once a case has been assigned to a Justice, that Justice drafts an opinion in the case after hearing oral argument and reviewing briefs from both parties and amicus curiae (friends of the court). The lead justice circulates the opinion for revisions to all of the Justices before deciding whether to release it. Once the Justices decide to issue an opinion, they typically publish it with a syllabus prepared by the Reporter of Decisions that summarizes all the opinions in the case.