Adversarial system

The adversarial system, also called adversary system, accusatorial system,^[1] or accusatory system,^[2] is a legal system used in the common law countries where two advocates represent their parties' case or position before an impartial person or group of people, usually a judge or jury, who attempt to determine the truth and pass judgment accordingly.^[3][4][5] It is in contrast to the inquisitorial system used in some civil law systems (i.e. those deriving from Roman law or the Napoleonic Code) where a judge investigates the case. The adversarial system is the two-sided structure under which criminal trial courts operate, putting the prosecution against the defense.

Adversarial systems are considered to have three basic features. The first is a neutral decision-maker such as a judge or jury. The second is presentation of evidence in support of each party's case, usually by lawyers. The third is a highly structured procedure.^[6] The rules of evidence are developed based upon the system of objections of adversaries and on what basis it may tend to prejudice the trier of fact which may be the judge or the jury. In a way the rules of evidence can function to give a judge limited inquisitorial powers as the judge may exclude evidence deemed to not be trustworthy, or irrelevant to the legal issue at hand.^[7] Peter Murphy in his Practical Guide to Evidence recounts an instructive example. A frustrated judge in an English (adversarial) court finally asked a barrister after witnesses had produced conflicting accounts, "Am I never to hear the truth?" "No, my lord, merely the evidence", replied counsel.

In criminal adversarial proceedings, an accused is not compelled to give evidence. Therefore, they may not be questioned by a prosecutor or judge unless they choose to be; however, should they decide to testify, they are subject to cross-examination and could be found guilty of perjury. As the election to maintain an accused person's right to silence prevents any examination or cross-examination of that person's position, it follows that the decision of counsel as to what evidence will be called is a crucial tactic in any case in the adversarial system and hence it might be said that it is a lawyer's manipulation of the truth. Certainly, it requires the skills of counsel on both sides to be fairly equally pitted and subjected to an impartial judge.

In some adversarial legislative systems, the court is permitted to make inferences on an accused's failure to face cross-examination or to answer a particular question. This obviously limits the usefulness of silence as a tactic by the defense. In the United States, the Fifth Amendment has been interpreted to prohibit a jury from drawing a negative inference based on the defendant's invocation of his or her right not to testify, and the jury must be so instructed if the defendant requests.

By contrast, while defendants in most civil law systems can be compelled to give statements, these statements are not subject to cross-examinations by the prosecution and are not given under oath. This allows the defendant to explain their side of the case without being subject to cross-examination by a skilled opposition. However, this is mainly because it is not the prosecutor but the judge who questions the defendant. The concept of "cross"-examination is entirely due to adversarial structure of the common law.

The name "adversarial system" may be misleading in that it implies it is only within this type of system in which there are opposing prosecution and defense. This is not the case, and both modern adversarial and inquisitorial systems have the powers of the state separated between a prosecutor and the judge and allow the defendant the right to counsel. Indeed, the European Convention on Human Rights and Fundamental Freedoms in Article 6 requires these features in the legal systems of its signatory states.

يُعدّ اعتراف المتهم بالجريمة أحد أبرز الفروقات بين النظام القضائي القائم على الخصومة والنظام القضائي القائم على الاستجواب. ففي النظام القائم على الخصومة، لا مجال للجدل، وتنتقل القضية مباشرةً إلى مرحلة النطق بالحكم؛ مع أن العديد من الأنظمة القضائية تشترط اعتراف المتهم بجريمته ؛ إذ لا يُقبل الاعتراف الكاذب الواضح حتى في محاكم القانون العام. في المقابل، في النظام القضائي القائم على الاستجواب، يُعتبر اعتراف المتهم مجرد دليل إضافي، ولا يُعفي اعترافه النيابة العامة من تقديم قضيتها كاملةً. وهذا ما يُتيح المساومة على الإقرار بالذنب في النظام القائم على الخصومة، وهو أمر يصعب أو يستحيل في النظام القائم على الاستجواب، ولذا تُحسم العديد من قضايا الجنايات في الولايات المتحدة دون محاكمة من خلال هذه المساومة. وقد باتت المساومة على الإقرار بالذنب أكثر شيوعًا في 27 دولة من دول القانون المدني. ^{[ 10 ]}

• تقييم الخصم
• قاعدة الاستبعاد
• نظام التحقيق
• التفسير القضائي
• التفكير المتوازي – يوصف بأنه بديل نظامي 

• كاجان، روبرت أ. (سبتمبر 2003). النزعة القانونية الخصومية: الطريقة الأمريكية للقانون . كامبريدج، ماساتشوستس: مطبعة جامعة هارفارد. ISBN 9780674012417.