The cognitive-motivational process model of learning describes how personality traits in a specific situation influence current learner motivation and through certain mediators, the learning outcome. This study investigates the influence of personality traits and current motivation on these mediators. For 86 high school students playing a simulation game, the Big Five, the need for cognition, current motivations, immersion, and joy of learning were measured. A hierarchical regression analysis showed that need for cognition, interest, and challenge significantly and positively impacts the experienced immersion. Also, the joy of learning correlates positively with immersion. The adapted model was partly supported: Results of this study can explain to some extent the interaction of personality traits and current motivation as well as their combined impact on immersion in live-action social science simulation games.