This article examines the effect of climate change on a type of armed conflict that pits pastoralists (cattle herders) against each other (range wars). Such conflicts are typically fought over water rights and/or grazing rights to unfenced/unowned land. The state is rarely involved directly. The rangeland of East Africa is a region particularly vulnerable to drought and livestock diseases associated with climate change. To analyze the possible effects of climate change on pastoral conflict, we focus our analysis on changes in resource availability, contrasting cases of abundance and scarcity. The role of resources is further contextualized by competing notions of property rights, and the role of the state in defining property and associated rights. We employ a contest success function (CSF) game-theoretic model to analyze the logic of range wars. This CSF approach emphasizes the low-level, non-binary nature of raiding behavior between pastoralist groups over limited natural resources. A central contribution of this approach is that the logic of raiding behavior implies a positive relationship between resources and conflict. This positive relationship is supported by several studies of the rangeland of East Africa, but is generally dismissed by the literature on the ‘resource curse’. This relationship is contingent on other factors examined in the model, producing the following results. First, the level of property rights protection provided by the state generally reduces conflict between pastoralist groups. Second, if property rights protection is provided in a biased manner, then conflict between pastoralist groups increases. Third, severe resource asymmetries between two pastoralist groups will induce the poorer group to become bandits (focusing their efforts on raiding and not producing), while the richer group raids in retaliation.