Italian civil law is full of provisions that hinder the preordained transmission of wealth, including, without doubt, the prohibition of succession agreements, sanctioned by art. 458 cod. civ. This experience suggests the rethinking of the dogma of the uniqueness of the testament as a regulatory tool for succession events in the Civil law system. Towards this functional goal, it compares with other legal systems, from which it emerges that sometimes successor agreements are peacefully admitted (for example in Germany), while in others, as in the French one, there are wide and significant exceptions to the prohibition, even though formulated in general terms. A possible harmonization of successor pacts in Europe, considering the EU Regulation 650/2012, can only take place effectively through ?the relativization of the hermeneutical procedure, based on a concrete balance of interests? and the realization of the objective represented by ?European citizenship?.