In adversarial systems, the defendant may plead "guilty" or "no contest," in exchange for reduced sentences, a practice known as plea bargaining, or a plea deal, 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 confession of guilt would not be regarded as ground for a guilty verdict. The prosecutor is required to provide evidence supporting a guilty verdict. But this requirement is not unique to inquisitorial systems, as many or most adversarial systems impose a similar requirement under the name "corpus delicti".