Victory or defeat in battle is modeled as a set of flow charts for dynamic simulation. Two main causal pathways are: from material resources via logistics to firepower at point of assault; and from organizational morale (emotional energy, coordination, discipline) to maneuver. According to empirical research by the author and others, the crucial event is organizational breakdown, which is more strongly affected by maneuver than by firepower of assault, and which leads to battle victory or defeat. Casualties are more strongly affected by organizational breakdown than by assault firepower. Additional pathways lead to attrition, feedbacks to material resources and to morale, and to long-term war outcomes and geopolitical consequences. Revolutions in military technology do not require a separate model or new theory, since all technological innovations operate by changing the strength of pathways in the basic model. These models give a more precise understanding of Clausewitzian friction or “fog of war.”