This scoping review synthesizes findings from a body of 62 empirical investigations to construct a framework that differentiates two primary forms of online romance scams: advance fee romance scams and investment-based romance scams. The analysis centers on mapping how these schemes operate and distinguishing their underlying mechanisms, goals, and technological sophistication. By organizing the literature into a typology, the work aims to clarify how different scam formats unfold and how victims are drawn into successive stages of exploitation, rather than treating romance fraud as a singular phenomenon. Both categories share an reliance on early emotional manipulation and the cultivation of trust, yet they diverge markedly in method and execution. Advance fee romance scams typically hinge on fabricated emergencies and sustained emotional grooming designed to secure repeated financial transfers over time. In contrast, investment-based variants—including pig-butchering schemes—employ fraudulent trading platforms, with a notable focus on cryptocurrency, to propel victims into escalating and cumulative financial commitments. This contrast underscores how scammers adapt tactics and technology to suit distinct crime scripts, even as they exploit similar affective vulnerabilities. The review draws on studies published between January 2024 and October 2025 in English and Chinese, presenting what it positions as the most comprehensive comparative synthesis to date. The inclusion of 62 studies enables cross-regional and cross-linguistic insights into offender networks, victim vulnerabilities, and prevention strategies, addressing a notable gap in prior literature that often treated romance scams as a monolithic phenomenon. The findings illuminate the industrialization and diversification of offender tactics, suggesting that these scams have become more systematized and scalable across different contexts. The work concludes by emphasizing the need for future research focused on guardianship and protective measures, a deeper understanding of victim psychology, and enhanced cross-border policy coordination to inform more targeted prevention and intervention frameworks.