The “50 percent rule” is an Israeli judicial doctrine that has played a pivotal role since the early 1960s in deciding disputes between the Israeli government and Palestinian landholders under Article 78 of the Ottoman Land Code. It was first institutionalized during a government land-claiming campaign aimed at providing state land for settlement-based Judaization of Israel's predominantly Palestinian Galilee region. Two decades later, during a similar state land-claiming campaign, the doctrine diffused into the occupied West Bank. Drawing on spatial components of social science diffusion literature and work in the field of legal geography, this article offers a legal-historical-geographical analysis of the evolution and diffusion of the 50 percent rule. Its conclusions suggest a new spatialized approach to the study of legal transfers and transplants that conceptualizes law's movement across international borders as one component of a broader process of legal diffusion, in which internal diffusion also plays an important role.