Conspiracy theories arise during important societal and political events, with negative consequences. Yet, conspiracy theories remain to be investigated in the context of sporting tournaments, in spite of the importance of such events in contemporary societies. During the 2018 FIFA World Cup, conspiracy theories alleging that the newly introduced video Assistant Referee (VAR) was used with malevolent motives gained popularity online. In this paper, we used a Twitter content analysis to explore VAR conspiracy theories during the World Cup (N = 2,768 tweets). Conspiracy tweets peaked after eliminations of some teams and were strongly associated with labels referring to self-categorization at the group-level, supporting the notion that conspiracy beliefs are triggered by contexts threatening one’s social identity. Conspiracy tweets were also correlated with tweets expressing skepticism or defiance against the VAR, suggesting that conspiracy beliefs might be related to sport fans’ other identity management strategies. Finally, we drew an intergroup typology of VAR conspiracy beliefs’ recurrent figures, highlighting that higher ordered categorization helped conspiracy narratives and content to adapt throughout the tournament. We discuss the identity management strategy status of sport fans’ conspiracy beliefs.