Learning in the twenty-first century is becoming more dependent on the use of digital tools and interactive media. Teachers play a crucial role in creating game-based learning procedures and enhancing learning and motivation. The aim of this article is to determine what kinds of expertise educators could require to effectively use game-based education (GBP). This study was done with 14 schools in East Java and their partner schools that took part in the GBP network initiative from 2017 to 2020. Two or three instructors at each school serve as the "core participants" who disseminate their knowledge to their colleagues. After collecting data via teacher documentation, theme interviews, and questionnaires, this research used qualitative content analysis to draw conclusions. The fields of pedagogy, technology, collaboration, and creativity were defined as the four key domains of competency. Researchers found that teachers' collaborative skills (whether intra-school or inter-school collaborations or networks with other teachers and key actors) were crucial to the success of the GBP's implementation. The findings may be used to improve pre-service and in-service teacher education and training, since teachers' game-based learning abilities will increasingly form an important part of their professional toolkits.