The U.S. Army has made the development of new concepts for land warfare a priority since the early 1980s. Unfortunately, few techniques have been available to help design or evaluate concepts in a rigorous, objective way. This report contains the results of a two-year effort to develop an intellectual framework for thinking about, designing, and evaluating land defense concepts. It is aimed at making the process by which the Army develops and evaluates concepts more rigorous and more efficient. The suggested improvements are of three types: (1) a typology — drawn from Army doctrine, NATO defense plans, and unofficial NATO defense concepts since the late 1940s — that allows different concepts to be described concretely and compared using a common vocabulary; (2) a review of the strengths and weaknesses of the Army's current approach for developing and evaluating concepts (the Concept-Based Requirements System, or CBRS) and a proposed analytic framework to ameliorate some of the shortcomings; and (3) a microcomputer-based, low-resolution Method of Screening Concepts of Warfare (MOSCOW), which can be used to refine and compare concept ideas in a systematic, quantitative way.