THE RULES OF THE GAME OF WAR

4. Communications

All a fighting unit's offensive and defensive value, and all its mobility, are entirely dependent on the necessity for that unit to remain in communication with one or another of its army's arsenals. Such communication includes the transmission of information and orders as well as the provision of supplies and munitions; it represents the organic integrity of an army. An arsenal may serve its own side only -- it cannot be conquered and used by the adversary; it may, however, be destroyed so as to deprive the enemy of its use.

A unit can neither move nor engage in combat unless it remains on a square which is in communication, either direct or indirect, with one of its own arsenals.

Direct communication means first of all that an arsenal can maintain contact with its side's forces along any vertical, horizontal or diagonal straight line radiating out from its own square; such lines may be of any length, save where mountains interrupt them. Note, for example, that all forts are positioned on an alignment of squares that puts them in permanent communication with one of their own arsenals. In addition, a line of communication may be reorientated, from any square along its trajectory, by a communications unit; such a unit is in effect a forward mobile echelon of the arsenal capable of redirecting communications for an unlimited distance along any straight line radiating out from whichever square it currently occupies. A second such unit placed on any square linked in this way to an arsenal by the first unit may further relay communications in precisely the same way from its own square.

At the start of play each side possesses one foot-communications unit capable of advancing one square at a time and one mounted-communications unit capable of moving two squares at a time. These non-fighting units have no offensive factor; their defensive factor is 1 and their range is two squares. They constitute a rich target in themselves for the adversary, so they need, if isolated, to be kept out of enemy range, and otherwise to be protected by an adequate number of fighting units. Communications units are the only units capable of movement while out of touch with an arsenal; during all such movements, however, they have no ability to redirect lines of communication.

Indirect communication means that each fighting unit remains in communication with any other fighting units of its own army which are in contact with it, that is to say, which occupy any of the eight immediately adjacent squares. Communication extends in this fashion to all units of the same army that are in physical contact with each other. Thus for an army or a detached force each unit of which is contiguous with at least one other, it is necessary and sufficient that just one unit be in direct communication with an arsenal or a relaying communications unit.

A fighting unit may move into a square where it is no longer in communication, directly or indirectly, with an arsenal. Once there, however, and so long as no communication is re-established either through contact with a friendly unit itself in direct or indirect touch with an arsenal, or else by virtue of the movement of a communications unit that reopens communication for it, the isolated unit is condemned to immobility and stripped of all offensive and defensive capacity. It is defenceless against attack and may be destroyed at will by any enemy unit stationed (or brought) within firing range. Note, however, that any friendly unit whose own communications are intact and which is within range to provide supporting fire thereby contributes its defensive factor to the defence of an isolated unit.

A line of communication is severed as soon as an enemy unit occupies any one of its component squares, and remains cut so long as that enemy unit maintains that position.

Where a line of communication is thus broken by an intervening enemy unit, it may be restored either directly or indirectly. Direct communication is re-established if the enemy unit is removed from the square it has occupied, whether of the enemy's own choice or because of the unit's destruction; it is also restored when the movement of friendly communications units manages to reinstitute contact via a new line of squares unoccupied by the enemy. Indirect communication is restored when friendly units whose movements are still unimpeded manage to link up with the unit or units whose communications have been cut by occupying any immediately adjacent square.

When one side has so well manoeuvred as to have cut off all or part of the enemy forces, at the end of its turn it may attack and destroy any one of the surrounded units that are within its range, and no resistance can be offered. Resistance cannot be resumed by the surviving units until such time as their communications have been restored. Where a detached force is surrounded by an enemy that has severed all its available lines of communication, it has but one avenue of hope: an attempt may be made as a last resort to liberate the surrounded force before it is completely destroyed by means of a relief force made up of friendly troops which have been able elsewhere to maintain or restore their communications; these rescuing troops must seek to penetrate the enemy front and so join up with the surviving units of the surrounded force.

In view of the vital importance of communication, strategy in this game is more often concerned with movement against the adversary's communications than with either offensive action directed against first one and then the other enemy arsenal, or with the wearing down of enemy strength by means of enduring superiority on the battlefront.

This emphasis also affects tactics, for the order of battle adopted at each moment must take into account not only the best positioning for the purposes of defence and counter-attack but also the best means of covering one's lines of communication. It is quite possible, even before the initial numerical balance of forces is upset, for an army to find itself on an unequal footing with its adversary because of a threat to its communications. An army whose battle lines become indistinguishable from its lines of communication will quickly lose its tactical manoeuvrability in engagements with the enemy, and may well find itself partly or completely surrounded. The destruction of a single unit can mean broken communications for a portion of an army, and this portion will be lost unless contact can be restored. Thus the outcome of a tactical engagement over just one square may have major strategical consequences.

While it is true that possession of only one of its two arsenals is a necessary and sufficient condition for an army to fight and win, it is nevertheless desirable that both arsenals be preserved for as long as possible, because on occasion this allows for a shift in the operational orientation of the entire force, and because it may help co-ordinate the movements of forces operating from different bases.