Autonomous vehicles (AVs) have the potential to save tens of thousands of lives, but legal and social barriers may delay or even deter manufacturers from offering fully automated vehicles and thereby cost lives that otherwise could be saved. Moral philosophers use “thought experiments” to teach us about what ethics might say about the ethical behavior of AVs. If a manufacturer designing an AV decided to make what it believes is an ethical choice to save a large group of lives by steering away from the large group towards a single individual, could the manufacturer be liable to that single individual? I believe the answer is yes. This article discusses famous “trolley problem” thought experiments in moral philosophy, which news articles have recently applied to AVs. After establishing a hypothetical case, applying product liability law to AV behavior may show a way, in some jurisdictions, that will permit a manufacturer to implement an ethical choice without triggering liability, but liability risk remains. I then turn to possible traditional defenses to see if they prevent liability for a manufacturer making what it believes is an ethical design choice—necessity, defense of self, and the sudden emergency doctrine. None of them provides an effective defense. Under current law, maximizing collision avoidance appears to minimize legal risk. I conclude that the only way to provide effective protection to a manufacturer seeking to implement ethical choices about AV behavior is through special legislation or regulation.