Everettian chance in no uncertain terms

The current landscape of views on the role of chance in the Everett interpretation is rocky. Everettians (Wallace, 2012; Sebens and Carroll, 2018; McQueen and Vaidman, 2019) agree that chance values should be derived using rules of rationality governing agents’ uncertain reasoning and/or decision-making, but they cannot agree on how. Critics (Baker, 2007; Dawid and Thébault, 2025; Mandolesi, 2019) maintain that these approaches are circular. We smooth the landscape by shifting focus from rules of rationality to physical facts on which Everettians agree: namely, the conditions under which branches are isolated. Our approach to isolation resolves the main tensions among the different Everettian chance derivations while clarifying how they avoid circularity.