Background and aims: Economic decision-making deviates from rational choice models and is influenced by social factors, particularly fairness considerations and belonging needs. Social exclusion and altruistic punishment are intended to promote behavioral conformity, yet paradoxically may exacerbate rather than correct targeted behaviors among individuals with addictions already experiencing chronic rejection. Several preliminary studies show that social exclusion increases money desirability in general populations, however, the interaction between acute social exclusion and economic decision-making among individuals with gambling disorders (PGs)-marked by aberrant financial decision-makingremains unexplored. Methods: In a field study, 203 gamblers were recruited outside gambling venues and randomized to experience either social inclusion or exclusion via Cyberball, a virtual ball-tossing paradigm. Participants then completed an ultimatum game, making accept/reject decisions on fair and unfair monetary offers, followed by the Problem Gambling Severity Index. Results: Social exclusion increased unfair offer acceptance among PGs but had no effect on low- and moderate-risk gamblers. PGs accepted more unfair offers following exclusion than inclusion. Gambling severity had no effect on unfair offers acceptance. Neither social exclusion nor gambling severity affected fair offer acceptance. Discussion and conclusions: Social exclusion triggered utilitarian decision-making only among PGs. This selective effect suggests rejection compromises PGs? economic decision-making processes, shifting priorities toward immediate monetary gains over equitable outcomes. These findings reveal how social punishment creates self-reinforcing cycles where exclusion triggers the utilitarian mindset characterizing problematic gambling. Treatment and societal approaches relying on social consequences may inadvertently strengthen harmful patterns, highlighting the need for inclusion-based interventions.  Kulcsszavak: social exclusion, economic decision-making, gambling, ultimatum game, altruistic punishment, ostracism