This research investigates the potential of a serious tabletop game to enhance the acquisition of Chinese idioms (chengyu) among adult learners of Chinese as a Foreign Language (CFL). Chengyu present particular challenges for second-language learners. To address this, a serious game was designed based on Learning Mechanic Game Mechanic framework. A small-scale evaluation was conducted with pre-, post-, and delayed-tests of idiom comprehension, Likert-scale surveys based on Keller’s ARCS model of Motivational Design, and semi-structured interviews. Findings suggest that the game improved learners’ comprehension of most idioms, with participants demonstrating stronger retention and deeper engagement compared to pre-test. Participants reported high levels of attention, confidence, and satisfaction, underscoring the motivational advantages of the game-based approach. Gameplay fostered memorable, embodied experiences likely to support long-term retention. This study highlights the promise of serious games in idiom pedagogy. It provides both empirical evidence and design recommendations for integrating serious tabletop games into CFL instruction, contributing to the broader field of game-based language learning.