How do narcissists respond to monetary rewards and are there differences in fairness sensitivity between different facets of narcissism? The present study (N = 287) investigated these questions using the Ultimatum Game, a behavioral decision-making task involving the presentation of advantageous and disadvantageous financial offers. The results of multilevel modeling revealed that individual differences in narcissism modulated responders’ game decisions: Individuals high in narcissism, particularly narcissistic rivalry, were more likely to accept monetary offers and this effect was even more pronounced for comparatively unfair offers. Results extend previous findings, suggesting that narcissists are hypersensitive to rewards and pay close attention how to maximize their personal profit rather than to enforce fairness norms.