The following is a partial list of landmark court decisions in the United States. Landmark decisions establish a significant new legal principle or concept or otherwise substantially change the interpretation of existing law. Such a decision may settle the law in more than one way:

• distinguishing a new principle that refines a prior principle, thus departing from prior practice without violating the rule of stare decisis;
• establishing a “test” or a measurable standard that can be applied by courts in future decisions.