There is a lot of evidence to support the claim that disadvantaged groups tend to have lower educational attainment, lower participation in early childhood education and lower performance in international assessments. The project iDecide proposes an innovative, forward-looking project, with the aim to support policy makers, school leaders and educators on how to develop inclusive policies and practices in their schools, particularly when these involve controversial issues (e.g. LGBTQ rights, Roma children’s education, mainstreaming education for learners with disabilities, integration of learners from migrant backgrounds). The project aims to develop an innovative toolkit and induction course to support evidence-based policy making that can lead to the reduction of disparities in learning outcomes and marginalization, by supporting school leaders, school staff, and policymakers to engage in shared and inclusive decision making. By implementing the toolkit and collecting rich data, we aim to understand the complexities of how decisions at school level influence marginalized groups and develop concrete recommendations for policy and practice on how to engage in shared decision making, giving voice to all stakeholders. The toolkit will be an easy to use package with resources to support school leaders and school staff to make decisions at the school level. It will include brief summaries of research findings, checklists, decision making flowcharts, practical tips, web tools and mobile web apps, along with details on how to engage in inclusive decision making at the school and policy levels. Schools from all partner countries will implement the toolkit for a year and rich evaluation data will be collected. Evidence based, concrete policy and practice recommendations will be provided that can reduce inequalities in education.