We are facing complex societal challenges, such as protecting the environment, promoting healthy living and fighting climate change. To address such challenges, citizens must be equipped with the ability to responsibly engage in scientific discussions and decisions. Traditional formal schooling has not been able to achieve this goal: There is a wide-spread lack of scientific knowledge at all level of society and students' interest in science tends to decline within school years. One reason is the decontextualised way in which science is taught. MULTIPLIERS aims to facilitate the transition of schools into innovative and open collectors of new ideas, practices, scientific approaches, able to offer to the communities in which they are embedded a space for open, inclusive and inquiry-based learning on science issues which have an impact on citizens' lives. This will be achieved by establishing multiplayers' partnerships (Open Science Communities, OSCs) involving schools, families, civil society organisations, informal education providers, policy-makers, the media and a vast range of science institutions in six EU countries, very different in terms of geographical and economic situation. OSCs will jointly select socio-scientific issues to be tackled and develop real-life projects to be implemented in schools involving more than 1500 students of all educational levels across six EU countries. Students will interact with a broad spectrum of science professionals and be involved in data collection and decision-making processes. Via open community events, they will then share and rethink their findings and experiences, liaising with families and society, acting as science multipliers. To ensure the results' transferability and uptake, final recommendations, guidelines, and learning materials will be published in an multilingual open webspace; OSCs will be maintained and enlarged after the end of the project to further pursue the MULTIPLIERS open schooling process.