The educational game development is a multidisciplinary software engineering process, where participate instructional and game designers, artists and programmers. Nevertheless, educators, who have an important role in the process, have limitations in authoring games at any moment to adapt them according to key educational aspects such as intended learning outcomes and their metrics, students’ learning styles, teaching and learning activities and embedded assessment. We propose a conceptual domain model that supports the development process of educational game authoring tools taking into account both educational and game domains. We consider authoring in two domains. In the educational domain, teachers configure/modify either generic activities with any curricular content, or specific learning activities with a concrete one. In the game domain teachers configure/modify game elements and challenges. Finally, we present two educational game authoring tools in the domain of maths supported by the proposed conceptual model.