An inquisitorial system is a legal system in which the court, or a part of the court, is actively involved in investigating the facts of the case. This is distinct from an adversarial system, in which the role of the court is primarily that of an impartial referee between the prosecution and the defence.

This adversarial system gives the opposing side the opportunity to compete in convincing the judge and jury based on the facts they present. In this situation, the Judge or Magistrate operates independently and is expected to deliver his judgement after hearing out each of the parties.