Collaboration is one of the main 21st century competencies that needs to be supported in children. Digital games can be a motivational technology for skills training in children, and have many benefits for children with special needs, including promoting social interaction and increasing pro-social behaviors, such as collaboration and cooperation. However, knowledge on how to design digital collaborative games to mediate and stimulate collaboration is scattered, and we know little about what gameplay design elements that support and mediate such collaborative interaction among children in special education. The current study aims to investigate how collaborative digital games can be designed to train collaboration skills in children in special education? The project will apply Design-Based Research, and the expected result is a taxonomy for design principles and game mechanics that can scaffold collaborative interactions in children in special education.