This article introduces and defines the concept of mediated receptive multilingualism as a mode of multilingual communication which eases understanding between typologically distant languages through the medium of a language closely related to the target. In an experimental setting, Estonians without previous exposure to Ukrainian were quite successful in understanding Ukrainian texts via their knowledge of Russian. As expected, they made use of various language-specific elements to improve intelligibility, such as linguistic similarities between Russian and Ukrainian. However, a number of extra-linguistic factors were detected as influential predictors of success, especially metalinguistic awareness, exposure to Russian, exposure to various registers, experience with multilingual situations, learnability, and attitudes towards Ukrainian. These findings contest a static take on multilingual potential and point out the emergent nature of competencies and practices that become relevant in multilingual settings. Unconventional communicative modes – like mediated receptive multilingualism – may activate linguistic and sociolinguistic resources needed for establishing understanding in novel and potentially challenging communicative settings.