The
adversarial system (or
adversary system) of law is the system of law that relies on the contest between each
advocate representing his or her party's positions and involves an impartial person or group of people, usually a
jury or
judge, trying to determine the truth of the case.
[1][2][3] As opposed to that, the
inquisitorial system has a judge (or a group of judges who work together) whose task is to investigate the case.
The adversarial system is generally adopted in common law countries. An exception, for instance in the U.S., may be made for minor violations, such as traffic offences. On the continent of Europe among some civil law systems (i.e. those deriving from Roman law or the Napoleonic Code) the inquisitorial system may be used for some types of cases.
The adversarial system is the two-sided structure under which criminal trial courts operate that pits the prosecution against the defense. Justice is done when the most effective adversary is able to convince the judge or jury that his or her perspective on the case is the correct one.
Some writers trace the process to the medieval mode of trial by combat[4][5], in which some litigants, notably women, were allowed a champion to represent them. The use of the jury in the common law system seems to have fostered the adversarial system and provides the opportunity of both sides to argue their point of view.
