Research assessing the persuasiveness of guilt has generally focused on appeals made to larger groups (collective guilt) or to individuals (personal guilt). However, a direct comparison of the two messaging strategies is crucial to discerning effective methods of behavior change in the context of risks to wellbeing where issue responsibility lies with the community at large and the burden of action to create measurable change is also shared. Furthermore, although efficacy messaging has been widely used to improve individuals' beliefs about their ability to engage in desired tasks and achieve goals, limited empirical evidence exists on the use of guilt and efficacy in concert to promote strategic communication outcomes. Informed by prior studies on guilt, efficacy, and collective emotions, the present research used a message-based intervention to experimentally manipulate the responsibility level of guilt (collective vs. personal) and the target level of efficacy (collective vs. self) in the context of an environmental health risk (Study 1, N = 211) and a socioeconomic risk (Study 2, N = 264). Across both studies, results indicated that pairing collective guilt appeals with self-efficacy messaging most effectively elicits risk-mitigating attitudes and intentions for shared problems. Beyond the theoretical implications for the literature on discrete emotions and persuasion, the findings highlight the need to consider both the type of guilt and efficacy appeals when designing campaigns that address collective concerns.