 Directed acyclic graphs present causal structure clearly, and so clarify in decision theory points that depend on causal structure. For example, Eells (2000) observes that choice is not genuine unless a decision screens off an act’s correlation with states. Joyce (2007: 546) uses a causal graph to depict how this may happen in a Newcomb problem that arises in a Prisoner’s Dilemma with a psychological twin. He shows that the Newcomb problem is a genuine choice despite correlation of acts and states because a decision screens off that correlation. Wolfgang Spohn (2012) constructs for Newcomb’s problem a causal model that distinguishes a decision and its execution and argues that given the model causal decision theory recommends one-boxing. An act in a decision problem may constitute an intervention in the causal model for the decision problem, as Meek and Glamour (1994) explain. Hitchcock (2016) and Joyce and Gibbard (2016) maintain that treating an act as an intervention enriches causal decision theory.