Intervention under Article 62 of the Statute of the International Court of Justice is an incidental proceeding which arises out of the main proceeding between States before the Court. Intervention pursuant to Article 62 is possible only if the decision in the case may affect an interest of a legal nature of a non-party State. The Court’s case law created the criteria that determine where that legal interest exists. The Court is inclined to find this interest when there is a material interest, that is, a certainty that the decision would either directly affect the volume or realm of rights exercised by the third-party state or would unavoidably affect jurisdictional matters affecting that state. In maritime cases the Court does not, as a rule, find a basis for recognizing the legal interest of a state seeking intervention. The presence of a basis for jurisdiction is not obligatory if a State intervenes as other than a party.