DESIGN The study is a school-based trial in three countries. Three separate trials will be conducted concurrently in Por clinical trials

Three gold-standard evaluations in Portugal, Czechia and the UK of an augmented social play intervention (Lina) to test its effects on belonging and costs for schools

This study looks at a new school activity called 'Lina' for 12-13 year olds in the UK, Portugal, and Czechia. It wants to see if Lina helps students feel more like they belong and improves their mental health, while also checking its cost for schools.