Objective: Academics, gambling regulators, and the gambling industry increasingly espouse a shared responsibility view of preventing gambling harm, considering individual gamblers and external stakeholders (e.g., gambling industry employees, government regulators, and public health workers) to be jointly responsible for this task. This study is the third in a series exploring gamblers' beliefs about responsibility for preventing gambling harm. Method: A sample of 4,336 subscribers to MGM Resorts International (MGM)'s loyalty card program as of January 2020 completed a web-based survey. Results: We observed that 58.1% of participants only held individual gamblers responsible for helping prevent gambling harm. However, two factors increased the likelihood of holding a shared responsibility viewpoint and assigning responsibility to casinos for reducing gambling harm: (a) scoring positive on the Brief Biosocial Gambling Screen (BBGS) or an Expanded Problem Gambling Screen (EPGS) and (b) being aware of GameSense, an onsite responsible gambling education program. Those who screened positive on the BBGS or EPGS also were more likely than their counterparts to deny personal responsibility for minimizing gambling harm to individual gamblers; that is, they were more likely to hold a purely external responsibility viewpoint. A meta-analytic year-over-year comparison revealed that compared to being aware of GameSense, screening positive for problem gambling was more strongly associated with assigning responsibility to casinos for minimizing gambling harm. Conclusions: We discuss these findings in the context of self-determination theory and suggest implications for health promotion and best practices for message design in responsible gambling programs. (PsycInfo Database Record (c) 2022 APA, all rights reserved).