Stand your ground laws (SYG) allow an individual to use deadly force against a perceived attacker anywhere that he or she has a legal right to be, without the requirement to attempt retreat before using deadly force. This article offers an analysis of SYG laws through a Sartrean existentialist lens. Drawing off existing empirical research and case examples, I make three claims: First, SYG laws have existential import to the extent that they influence individuals’ beliefs, behavior, and judgments. Second, this existential import makes individuals more likely to perceive situations as threatening and find reasons to be afraid. Third, the phenomenological experience of negative emotions such as fear and anger affects our ability to make careful and reasoned judgments regarding the amount of threat we face. I build my case for these three claims using Sartre’s concept of fundamental project, or the image of self used to organize one’s existential possibilities. I also use Sartre’s phenomenological account of emotion and Robert Solomon’s account of emotion, which has Sartrean roots. I argue that, based on my analysis, the right to use self-defense should include the duty to retreat when possible.