The opportunistic debitage, originally adapted from Forestier's S.S.D.A. definition, is characterized by strong adaptability to local raw material morphology and its physical characteristics and it is oriented towards flake production. Its most ancient evidence is related to the first European peopling by Homo sp. during Lower Pleistocene starting from 1.6 Ma and gradually increasing around 1 Ma. In these sites, a great heterogeneity of the reduction sequences and raw materials employed is highlighted, bringing to the identification of multiple technical behaviours. However, the scientific community does not always agree on associating the concepts of opportunism and method to describe these lithic complexes. The same methodological issues remain for the Middle Pleistocene where, simultaneously to an increase of the archaeological evidence and the persistence of the opportunistic debitage, the first bifacial complexes are attested. Further implications concerning the increasing complexity highlighted in core technology management are now at the centre of an important debate regarding the genesis of more specialized method (Levallois and Discoid) especially during MIS 12 and MIS 9. We suggest that the opportunistic debitage could be the starting point for this process, carrying a great methodological and cultural potential within itself.