Article 18. [Provisions to secure protection of law]

(5) No person who shows that he has been tried by a competent court for a criminal offence and either convicted or acquitted shall again be tried for that offence or for any other criminal offence of which he could have been convicted at the trial for that offence, except upon the order of a superior court in the course of appeal or review proceedings relating to the conviction or acquittal.

(6) No person shall be tried for a criminal offence if he shows that he has been pardoned for that offence.

Article 20
Ne bis in idem
1. Except as provided in this Statute, no person shall be tried before the Court with respect to conduct which formed the basis of crimes for which the person has been convicted or acquitted by the Court.
2. No person shall be tried by another court for a crime referred to in article 5 for which that person has already been convicted or acquitted by the Court.
3. No person who has been tried by another court for conduct also proscribed under article 6, 7 or 8 shall be tried by the Court with respect to the same conduct unless the proceedings in the other court:
(a) Were for the purpose of shielding the person concerned from criminal responsibility for crimes within the jurisdiction of the Court; or
(b) Otherwise were not conducted independently or impartially in accordance with the norms of due process recognized by international law and were conducted in a manner which, in the circumstances, was inconsistent with an intent to bring the person concerned to justice.