The purpose of the paper is threefold. First, ir presents empirical data about paternal and maternal games displayed with toddlers in a ptay situation with polyvalent objects. Both parents proposed predictable routines through conventional games. But differenees in parental games also occurred, as fathers proposed new ways of using the objects through non conventional games more than mothers did. Second, those results are interpreted in terms of paternal specific contributions to development, ln fact, in such play situations with toddlers, pc, ternal behaviors are more destabilizing than maternal ones. Last, we di~cuss whether paternal irregularities in such play situation with ok,]ects may favor cognitive development, as well as structurant maternal regularities in the same situation. More generally, the complementa,p~ contributions of maternal and paternal perturbations in different kind of situations (play, language developmenO are questioned.