Multilingual systems raise the fundamental question of the quality of legal translation. This article examines the question from the perspective of the actors involved, rather than from that of institutional procedures. Issues specific to contexts of official multilingualism are analysed in relation to problems associated with translation competence, with a view to drawing relevant conclusions for translator training. In multilingual systems, legal translation is subject to particular requirements related to intertextuality, the status of the translated text, the multiplicity of target readers, and the institutionalization of the text production process. These requirements have numerous implications, which are studied here within the framework of general models of competence and their interdisciplinary potential as they pertain to legal translation. It is argued that the question of official multilingualism should be integrated into training based on professional situations by emphasizing the following aspects: the rational use of documentary resources, the acquisition of knowledge relating to language law and the functioning of institutions, the avoidance of linguistic interference and jargon, and the ability to debate and interact with the various stakeholders. In conclusion, the uniqueness of the many different multilingual contexts is highlighted, thereby calling into question the idea that these contexts represent a simplified situation for legal translation construed solely in terms of technical competencies.