A critical scientific and societal challenge consists in developing and evaluating interventions that reduce prejudice towards outgroups. Video games appear to be a promising method but a number of falls in the current scientific literature prevents to fully understand the potential sizeable impact of video games on reducing prejudice. The present study investigated to what extent a video game designed to reduce prejudice towards minorities in a fictional society has the potential to reduce prejudice towards non-fictional minorities. Participants played either a recently developed game designed to reduce prejudice towards non-fictional minorities (hereafter referred to as the test game) or a control game. After playing at home, participants performed two tasks in a lab context. We observed overall a positive effect of playing the test game compared to the control game on attenuating prejudice towards an outgroup individual. We indeed observed that players of the control game had more midfrontal theta activity, reflecting more cognitive conflict, when they acted prosociality towards the outgroup participant and a lower neural response to the pain of the outgroup participant compared to the ingroup participant. These effects were attenuated for players of the test game. We also observed that players of the test game had a higher sense of agency when they decided to help the outgroup participant compared to when they did not help the outgroup participant, an effect not observable in players of the control game. These results are promising as they support evidence that using fictional characters in video games may induce positive changes towards non-fictional individuals.