Video games are hugely popular, generating more than twice the revenue of global movie and music industries combined. Whilst technically illegal and often carrying negative connotations, modding constitutes a moral grey area that is commonly accepted, often encouraged by proprietary owners and forum-centred gaming communities. Literature reflects a disparity between outsider and insider perceptions of modding, with a paucity of studies reflecting insider perspectives. Using Reddit forum data, this study contributes insight into perceptions of modding held by gamers and ‘modders’, as described in their words and their territory. Thematic analysis revealed four main themes relating to unfairness in the vendor community, modders as antagonists, differences between modders and modding as forms of self-defence. Conclusions include that modding appears to have both pro- and antisocial applications, but many people and organisations demonise modders as a homogeneous group, which may encourage antisocial behaviours.