Libertarian free will is, roughly, the view that agents (or, agent-involving events) cause actions to occur or not occur: Maddy's decision to get a beer causes her to get up off her comfortable couch to get a beer, though she almost chose not to get up. Libertarian free will notoriously faces the luck objection, according to which agential states do not determine whether an action occurs or not, so it is beyond the control of the agent, hence lucky, whether an action occurs or not: Maddy's reasons for getting beer in equipoise with her reasons to remain in her comfortable seat do not determine that she will get up or stay seated, so it seems beyond her control, hence lucky, that she gets up. In this paper I consider a sub-set of the luck objection called the Physical Indeterminism Luck Objection, according to which indeterministic physical processes cause actions to occur or not, and agent's lack control over these indeterministic physical processes, so agent's lack control over, hence it is lucky, whether action occurs or not. After motivating the physical indeterminism luck objection, I consider responses from three recent event-causal libertarian models, and conclude that they fail to overcome the problem, though one promising avenue is opened up.This paper is divided into six parts. In Section One, I minimally define libertarian free will as accepting agential indeterminism, which is the conjunction of indeterminism and agential causation, where agential indeterminism occurs when an agent's reasons, efforts or character indeterministically cause actions. In Sections Two and Three I outline the physical indeterminism luck objection to libertarian free will, which states that sub-agential physical processes in the brain indeterministically cause actions to occur, and agents lack control over these indeterministic physical causes, so agent's lack control over whether their actions occur. If agent's lack control over whether actions occur, the occurrence of these actions is lucky, where this luck jeopardizes free will and moral responsibility. In Sections Four through Six I consider three recent libertarian responses to this objection-Mark Balaguer in Section Four, Chris Franklin in Section Five, and Robert Kane in Section Six. I conclude that none of these models satisfactorily overcomes the physical indeterminism luck objection, though one interpretation of Kane yields a promising avenue of reply.
