The paper reports on the design process of a transmedia game driven by narratives mixing fact with fiction. The aim of the game was to enhance student motivation, collaboration, multiliteracy and local history learning. Atotal of 378 students ages 14-16 from three municipalities in Sweden played the game in their local school, providing content, reflections and suggestions for this type of gamification in school; thus supporting the design. The game improved students' multiliteracy skills while physically visiting and exploring local historical sites. Working in groups to solve tasks improved collaboration skills. Being placed in a fictional setting supported engagement.