Gacha Mechanics and Fear of Missing Out in Free-to-Play Mobile Games: Implications for Player Engagement, Satisfaction, and Sustainable Monetisation

Abstract

Gacha mechanics have become an important monetisation device in free-to-play mobile games by combining randomised rewards, rarity, limited-time content, and repeated transactions. This article examines how gacha mechanics and Fear of Missing Out (FOMO) jointly relate to player engagement, satisfaction, and sustainable monetisation. A structured integrative literature review and thematic synthesis were conducted using a coded analytic corpus of 22 peer-reviewed journal articles, supplemented by supporting peer-reviewed literature for conceptual and regulatory context, with direct gacha evidence distinguished from adjacent evidence on loot boxes and broader microtransactions. Random rewards and scarcity cues are consistently associated with attention, repeated play, purchase intention, and commitment through anticipation, symbolic value, time pressure, and accumulated investment. However, high engagement does not necessarily indicate high satisfaction. Opaque probabilities, weak cost visibility, repeated disappointment, and aggressive choice architecture are associated with lower perceived fairness and trust. This article defines sustainable monetisation as repeatable revenue generation across live-service content cycles that remains compatible with voluntary engagement, informed choice, perceived fairness, trust, and manageable reputational and regulatory risk. Because the reviewed studies rarely measure long-term firm-level financial performance directly, this outcome is treated as a conceptual business inference rather than an empirically tested financial endpoint. The integrated framework therefore proposes fairness and trust as conceptual boundary conditions that may shape whether engagement develops into voluntary loyalty or disengagement.