Abstract: The article debunks the consensus that in concerted action, concurrent causes and alternative liability situations, the actual causation requirement is missing. While courts and scholars insist that in these cases tort law holds liable parties who clearly did not cause the victim’s harm, this article offers a novel approach. Using a simple model and applying it to leading decisions, it shows that a party who did not and could not even potentially injure the victim could nevertheless be a but-for reason for the harm. The article also challenges claims that causation theories like concerted action, substantial factor and alternative liability are fair to the victim or that they are designed to deter actors from engaging in “antisocial” activities. In deviation from the prior literature, this article reveals that these causation theories reduce the parties’ incentives to take care and result in more, rather than fewer, accidents. This article further shows that, despite lip service to the contrary, tort law promotes harmful activities that judges declare immoral, antisocial and illegal. The article argues, however, that in many cases this result can be justified on efficiency grounds. The article concludes that the but-for test should have a larger role in causation analysis, and it provides a number of policy recommendations to courts and lawmakers.