In this study we propose a set of linked systematic reviews to synthesize what is known about the impact of laws that relax civilian rights to use lethal force in self-defense. These are the first systematic reviews on this policy-relevant topic. The three systematic reviews proposed are: (a) a quantitative synthesis of absolute impacts of changes to state laws; (b) a quantitative equity synthesis of the relative effects of such changes to the law between different socio-demographic groups (i.e. the differential effects for ethnic minority, gender and other groups); and (c) a qualitative synthesis of literature exploring intermediary social processes (e.g. increased fear of victimization) that help to explain how and why any observed effects may occur. Bringing these linked systematic reviews together will allow us to understand variation in impact across political jurisdictions and explain how changes to macro-level legislative factors can affect population behaviours around violence and personal safety.