The project starts from the growing complexity of family structures in contemporary societies, in which multiple parental figures sometimes concur with respect to minors, who occupy positions and have different roles, and aims to analyze them and, where appropriate, outline them normatively through the concept of multi-parenting and the application of various regulatory techniques used in comparative law (flexibility of legal parenting, diversification of legally relevant parenting, diffraction of the effects of parenting). The project is aligned with the theses that, at an international level, propose to re-evaluate from the law complex personal and family relationships that are often made invisible or developed informally. The project pays particular attention to two family realities in which the multiparental model is very present (families resulting from homoparental relationships that can evolve towards collaborative forms of parenting, and reconstituted families after a marital or couple crisis) and incorporates the study of the problems of its cross-border recognition. The implementation of normative criteria aimed at responding to complex family realities can have highly beneficial effects for all parties involved in a parental relationship. For adults, it can seek official recognition of certain parental roles or functions, as well as greater legal certainty in essential aspects of personal and family life such as reproductive decisions or the upbringing and education of children, and the consequent assumption of procreative and/or parental responsibilities.