Evidence suggests that violent media influence users’ cognitions, affect, and behavior in a negative way, whereas prosocial media have been shown to increase the probability of prosocial behavior. In the present study, it was tested whether empathy moderates these media effects. In two experiments (N = 80 each), inducing empathy by means of a text (Study 1) or a video clip (Study 2) before playing a video game caused differential effects on cognitions and behavior depending on the nature of the subsequent video game: The induction had positive effects on participants’ behavior (i.e., decreasing antisocial and increasing prosocial behavior) after a prosocial game (Study 1), or when participants played a positive hero character in an antisocial game (Study 2). In contrast, empathy increased antisocial behavior and reduced prosocial behavior after playing a mean character in an antisocial game (Study 1 and 2). These findings call attention to the differential effects of empathy depending on game type and game character, thereby questioning the unconditional positive reputation of empathy in the context of video game research.