This article aims at an analysis of agreements as to succession from the perspective of private international law. All forms of succession agreements are considered, including mutual wills. The study also contains references to comparative law in the field. The relevant provisions of Regulation (EU) No 650/2012 of the European Parliament and of the Council of 4 July 2012 on jurisdiction, applicable law, recognition and enforcement of decisions and acceptance and enforcement of authentic instruments in matters of succession and on the creation of a European Certificate of Succession – are analyzed. 650/2012, distinguishing between unilateral and bi- or multilateral pacts, as well as between the admissibility of pacts and issues related to their validity, including binding force and provisions on termination. The article concludes with a functional analysis dedicated to adapting the effects of agreements as to succession, wich are valid according to the hypothetical succession law, given that the lex successionis is hostile to them. More specifically, there is the issue of protecting the interests of force heirs by reference to the law applicable to the succession.