This essay explores an emerging issue in the criticism of the “bundle” conception of property: whether embracing the right to exclude as the core of property is sufficiently determinate to avoid the same disintegrating effects as the bundle conception. Thomas Merrill and Henry Smith believe so, and they have developed an extensive account of what I call the “exclusion conception of property.” It is initially alluring as a solution to the problems caused by the bundle conception, but this is a false promise. Merrill and Smith are correct that the bundle conception is wrong, but their model of how the right to exclude functions in practice—what they call an “exclusion strategy”—cannot account for the substantial majority of property doctrines that are the subject of litigation. In practice, most property disputes arise not from intentional trespass and similar situations in which exclusion is the essential issue, but rather from ex ante relationships between individuals concerning the use, possession and disposition of property rights. Although Merrill and Smith claim that such doctrines are “governance strategies” that allegedly function only at the periphery of property law, these doctrines actually comprise the majority of property cases, including many trespass cases. Although trespass is supposed to represent the exclusion strategy par excellence, affirmative defenses and other counter-claims representing the so-called “governance strategies” often constitute the bulk of the actual litigation. Although the elegant reductionism of the exclusion conception makes it theoretically appealing, lawyers and economists should be wary of its promise of determinacy in saving property from the disintegrative effects of the bundle conception.