This study investigates how the perceived congruity of an in-game advertisement with the game environment and its perceived interactivity affect fantasy game players’ perceived ad intrusiveness, narrative realism and, ultimately, their overall attitude toward in-game advertising (IGA). We also show how players’ general attitude toward advertising moderates these effects. The results of two experimental studies with active fantasy game players (N = 597/ N = 613) indicate that perceived ad congruity and interactivity both benefit fantasy game players’ attitude to IGA by reducing the perceived ad intrusiveness and positively contributing to the perceived realism of the fantasy game. Additionally, the positive effects of perceived ad congruity and interactivity through ad intrusiveness are positively reinforced by players’ general attitude toward advertising, while the effects through narrative realism are attenuated by players’ general attitude toward advertising.