The rapid advancement of digital technologies has intensified interest in innovative educational approaches such as gamification and simulation-based learning (GSBL) in science education. Despite their documented pedagogical benefits, teachers’ adoption of these approaches remains limited. This study examines the determinants of in-service science teachers’ intention to use GSBL through the Unified Theory of Acceptance and Use of Technology 2 (UTAUT2). A cross-sectional survey design was employed with a sample of 800 in-service science teachers who participated in a structured professional development program. Structural equation modeling (SEM) was used to test the proposed research model and hypotheses. The results indicate that performance expectancy, effort expectancy, social influence, facilitating conditions, hedonic motivation, price value, and habit significantly predict teachers’ behavioral intention to adopt GSBL. The findings contribute to the literature by validating UTAUT2 in the context of science education and by offering practical implications for policymakers, teacher educators, and school administrators seeking to promote technology-enhanced pedagogies.