The ethic of priority is a compromise between the extremely compensatory ethic of outcome equality and the needs‐blind ethic of resource equality. We propose an axiom of priority and characterize resource‐allocation rules that are impartial, prioritarian, and solidaristic. They comprise a class of rules that equalize across individuals some index of outcome and resources. Consequently, we provide an ethical rationalization for the many applications in which such indices have been used (e.g., the human development index, the index of primary goods, etc.).