THE RULES OF THE GAME OF WAR

3. Tactical Engagement

An attack on an enemy unit consists of the concentration of one's fire -- or, in the case of a cavalry attack, the directing of a charge -- upon the square which that unit is occupying. An attack is carried out by a certain number of one's own units that have come within range of the enemy unit's position.

First the offensive factors of all units in a position -- and within range -- to attack the targeted unit are added up. Then the defensive factors of all opposing units in a position -- and within range -- to fire upon the targeted unit (including that unit itself) are likewise added up. Where total offensive strength, so arrived at, is inferior or equal to total defensive strength, the targeted unit resists. Where total offensive strength is superior by two or more points, the targeted unit is destroyed; this event entails no obligation upon the attacker to occupy the position thus vacated. Where total offensive strength exceeds total defensive strength by just one point, the unit attacked must abandon its position, and this, obligatorily, as the first of the five moves constituting its side's next turn. Moreover, the dislodged unit may not contribute as part of that next turn in any attack: in other words, its offensive factor does not count even if it is within range of an enemy unit now under counter-attack. Lastly, where a unit defeated by one point is unable to vacate its position in this way as the first move of its side's following turn, all surrounding squares being occupied by friendly or hostile units, the defeated unit is ipso facto destroyed.

The necessity of paying maximum attention to the tactical defence of every single unit is imposed by the fact that even a slightly prolonged inferiority in tactical encounter leads to a unilateral attrition of numerical strength. Any such quantitative loss, which is in any case ominous from a strategic standpoint, may moreover quickly turn, on the tactical plane, as soon as an army's total offensive strength sinks so low as to preclude all counter-attack, into an irreversible qualitative inferiority on the battlefront.