This study examined the effectiveness of Nihongo Quest, a theory-driven role-playing game (RPG) developed for beginner learners of Japanese. Sixty undergraduate students participated in an eight-week quasi-experimental study comparing a game-based learning (GBL) condition with a traditional textbook-based condition. Results indicated that participants in the GBL group demonstrated significantly greater gains in vocabulary ( d = 1.45) and grammar ( d = 1.05) than those in the textbook group. In addition, the GBL group reported higher levels of intrinsic motivation ( η ² = .25) and lower levels of language learning anxiety ( η ² = .16). These outcomes are attributed to the game’s systematic alignment with core second language acquisition (SLA) frameworks, including the input–interaction–output (IIO), self-determination theory (SDT), willingness to communicate (WTC), and sociocultural theory (SCT). Through the integration of multimodal literacy tasks, interactive dialogues, and culturally situated scenarios, Nihongo Quest reduced cognitive load while supporting both linguistic and pragmatic development. The findings suggest that theory-informed RPG-based instruction can effectively enhance beginner-level Japanese language acquisition and offer a transferable instructional design model for other complex-script languages, such as Chinese and Korean.
Wang et al. (Wed,) studied this question.