The fast development of digital platforms has changed the financial and social behaviors of young adults in Indonesia, but also has allowed the emergence of unlawful online gambling, illicit loans and transactional relationships. Although these phenomena are typically treated in isolation, there is little study that examines their interactions as part of a larger process of vulnerability. The aim of this study is to examine the sequential association proposed between online gambling, illegal online loans, and sugar daddy relationships among Indonesian young adults. The paper develops a sequential vulnerability paradigm through a synthetic review technique that integrates empirical data from behavioral, psychological, legal, and socio-economic literature. The literature suggests a common pattern of escalation in which online gambling is an entry point to financial risk, followed by gambling-related losses leading to reliance on illegal online loans that exacerbate psychological discomfort from debt accumulation. Some young individuals, especially women, resort to transactional relationships as a high-risk coping technique when they are under protracted financial and emotional stress. The synthesis points to debt stress as a proposed key link between gambling and negative mental health and social effects, consistent with mediation evidence reported in the source studies. The study also shows how vulnerability is increased at every point of the cycle by factors such as digital accessibility, targeted marketing, poor financial literacy and ineffective regulatory enforcement. Building on a theoretical approach that combines behavioral and structural views, this research extends the understanding of digital financial harm in emerging economies and emphasizes the need for a coordinated policy response that addresses gambling legislation, predatory lending, and psychosocial support simultaneously.