<p>Gamification has been widely used in mobile-assisted language learning (MALL) as a means of enhancing learner engagement. Understanding factors related to learner acceptance is important for the successful usage of gamified applications in MALL. This study investigates the key factors associated with user acceptance of gamified vocabulary apps in an English as a Foreign Language (EFL) context in higher education. This investigation is based on an extended Unified Theory of Acceptance and Use of Technology (UTAUT) model that re-integrates learner attitude. In the context of voluntary language learning, attitude is hypothesised as a key mediating variable of the relationship between core constructs and behavioural intention. This study used partial least squares structural equation modelling (PLS-SEM) to examine cross-sectional survey data collected from 232 Chinese university students. The results show that the main constructs in the UTAUT framework, including performance expectancy, social influence and facilitating conditions, did not demonstrate statistically significant direct effects on students’ behavioural intentions. Instead, the analysis found significant indirect effects, indicating that the predictive relationship between the model’s core constructs and the intention to use the apps is contingent upon learner attitude. Attitude was the only factor that showed a direct and significant relationship with intention, emerging as the strongest predictor. These findings highlight the value of including attitude in the UTAUT model for language learning contexts and support its importance in predicting students’ intentions to use educational technologies. Practically, this suggests that efforts to promote technology use should focus on cultivating positive learner attitude rather than merely emphasising the features of the tools or social endorsement.</p>