The article proposes a remodeling of Tertiary Language Didactics (TLD) against the backdrop of empirical findings from German-speaking areas and the notions of translanguaging and "compétence plurilingue." TLD as a multilingual didactics approach for the initial stages of L3 learning developed in the 1990s in the field of "German as a foreign language after English" ("DaFnE") as a response to the specificity of L3 learning conditions (age, intellectual development, different domains of prior knowledge in other languages). Later, the approach, with its overarching principle of cognitive learning and teaching, was generalized to other language constellations (Hufeisen & Neuner, 2003; Neuner et al., 2009). By reviewing selected studies from the 1980s up to 2021, our remodeling highlights the importance of transfer not only in L3 reception, but also in L3 production and practice. In order to economize L3 learning, TLD 2.0 proposes to focus on cognates in reception and production (perceived and assumed cross-linguistic similarities) and streamlined grammar teaching (deduction-practice combinations, parallel exercises). Informed by the discourses of translanguaging and "compétence plurilingue," we also discuss the role of less "visible" knowledge stores that bi- or plurilingual L3 learners may have and the possibility of activating skills in previously learned or acquired languages (two-language tasks) in pursuit of education goals beyond L3 learning.