Previous studies have suggested that understanding the relationships and developmental paths among TPACK constructs plays a crucial role in teachers' TPACK development process. Researchers (Chai et al.," Edu Technol Soc" 13(4):63-73, 2010) have found that technological knowledge, pedagogical knowledge, and content knowledge are all significant predictors of pre-service teachers' TPACK. Thus, one of the major concerns that educators may have is, which type of knowledge should come first in an educational technology course in order to enhance the participants' TPACK. This study was conducted to examine the effects of the technology- and pedagogy-oriented course design on improving in-service preschool teachers' technological pedagogical content knowledge-Games (TPACK-G) as well as their acceptance of digital game-based learning. The participants were 49 in-service preschool teachers. They were assigned into a technology- and a pedagogy-oriented group. The results show that when integrating the TPACK-G framework into the preschool context, teachers who were taught with game knowledge first tended to have higher competencies in game knowledge and game pedagogical content knowledge than those who were first instructed with game pedagogical knowledge.