<P> In an adversarial system, judges focus on the issues of law and procedure and act as a referee in the contest between the defense and the prosecutor . Juries decide matters of fact, and sometimes matters of the law . Neither judge nor jury can initiate an inquiry, and judges rarely ask witnesses questions directly during trial . In some American jurisdictions, it is common practice for jurors to submit questions to the court that they feel were not resolved in direct or cross-examination . After testimony and other evidence are presented and summarized in arguments, the jury will declare a verdict (literally: "the spoken truth") and in some jurisdictions the reasoning behind the verdict . However, the discussions among jurors cannot be made public except in extraordinary circumstances . Appeals on the basis of factual issues, such as sufficiency of the sum total of evidence that was properly admitted, are subject to a standard of review that is in most jurisdictions heavily deferential to the judgment of the fact - finder at trial, be that a judge or a jury . The failure of a prosecutor to disclose evidence to the defense, for example, or a violation of the defendant's constitutional rights (legal representation, right to remain silent, an open and public trial) can trigger a dismissal or re-trial . In some adversarial jurisdictions (e.g., the United States), a prosecutor cannot appeal a "not guilty" verdict (absent corruption or gross malfeasance by the court). </P> <P> In adversarial systems, the defendant may plead "guilty" or "no contest" in exchange for reduced sentences, a practice known as plea bargaining, which is an extremely common practice in the United States . In theory, the defendant must allocute or "voice" his or her crimes in open court, and the judge must believe the defendant is telling the truth about his or her guilt . In an inquisitorial system, a mere confession of guilt would not be regarded as ground for a guilty verdict, and the prosecutor is required to provide evidence supporting a guilty verdict; however, this requirement is not unique to inquisitorial systems, as many or most adversarial systems impose a similar requirement under the name corpus delicti . </P> <P> Until the development of the Medieval Inquisition in the 12th century, the legal systems used in medieval Europe generally relied on the adversarial system to determine whether someone should be tried and whether a person was guilty or innocent . Under this system, unless people were caught in the act of committing crimes, they could not be tried until they had been formally accused by their victim, the voluntary accusations of a sufficient number of witnesses, or by an inquest (an early form of grand jury) convened specifically for that purpose . A weakness of this system was that because it relied on the voluntary accusations of witnesses, and because the penalties for making a false accusation were severe, victims and would - be witnesses could be hesitant to actually make their accusations to the court, for fear of implicating themselves . Because of the difficulties in deciding cases, procedures such as trial by ordeal or combat were accepted . </P> <P> Beginning in 1198, Pope Innocent III issued a series of decretals that reformed the ecclesiastical court system . Under the new processus per inquisitionem (inquisitional procedure) an ecclesiastical magistrate no longer required a formal accusation to summon and try a defendant . Instead, an ecclesiastical court could summon and interrogate witnesses of its own initiative, and if the (possibly secret) testimony of those witnesses accused a person of a crime, that person could then be summoned and tried . In 1215, the Fourth Council of the Lateran affirmed the use of the inquisitional system . The council also forbade clergy from conducting trials by ordeal or combat . As a result, in parts of continental Europe, the ecclesiastical courts operating under the inquisitional procedure became the dominant method by which disputes were adjudicated . In France, the parlements--lay courts--also employed inquisitorial proceedings . </P>

Common law countries such as australia use the inquisitorial system of dispute resolution