This briefing Note describes a new ground combat vehicle concept called Ninja. The Ninja concept envisions a light, agile, survivable fighting system based on a single crewman in supervisory control of multiple, intelligent robotic subsystems. The subsystems comprise most of the major functional modules of the combat vehicle, e.g., propulsion, navigation, target acquisition and engagement, sensors, and communications. Ninja holds the potential to reduce vehicle size from current norms without proportionately reducing combat effectiveness, by shifting to automated subsystems many tasks that have traditionally required several human crew members. Remaining tasks--largely supervisory and decision-oriented--are assumed by the single crewman. This Note discusses the Ninja concept, along with its motivation and rationale; performance goals in the areas of firepower, transportability, survivability, and life-cycle costs; potential tactical targets; research areas; and a proposed Defense Advanced Research Projects Agency technology development and demonstration program.