Mootness

In law, the terms moot and mootness have different meanings in British English and American English.

In the legal system of the United States, a matter is moot if further legal proceedings with regard to it can have no effect, or events have placed it beyond the reach of the law. Thereby the matter has been deprived of practical significance or rendered purely academic. The U.S. development of this word stems from the practice of moot courts, in which hypothetical or fictional cases were argued as a part of legal education. These purely academic issues led the U.S. courts to describe cases where developing circumstances made any judgment ineffective as "moot". The doctrine can be compared to the ripeness doctrine, another judge-made rule, that holds that judges should not rule on cases based entirely on anticipated disputes or hypothetical facts. Similar doctrines prevent the federal courts of the United States from issuing advisory opinions.

This is different from the usage in the British legal system, where the term "moot" has the meaning of "debatable". The shift in usage was first observed in the United States.

In the U.S. federal judicial system, a moot case must be dismissed, there being a constitutional limitation on the jurisdiction of the federal courts. The reason for this is that Article Three of the United States Constitution limits the jurisdiction of all federal courts to "cases and controversies". Thus, a civil action or appeal in which the court's decision will not affect the rights of the parties is ordinarily beyond the power of the court to decide, provided it does not fall within one of the recognized exceptions.

A textbook example of such a case is the United States Supreme Court case DeFunis v. Odegaard, 416 U.S. 312 (1974). The plaintiff was a student who had been denied admission to law school, and had then been provisionally admitted during the pendency of the case. Because the student was slated to graduate within a few months at the time the decision was rendered, and there was no action the law school could take to prevent that, the Court determined that a decision on its part would have no effect on the student's rights. Therefore, the case was dismissed as moot.

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