Shock Army was the name given to the elite fighting units of the Republican 'Ejercito Popular' (The Popular Army). The game recreates a number of attacks by these spearhead corps. Shock Army is designed to be played as a table top game between two players. No map is included, but there are sufficient terrain features to fight four major scenarios. The game is built around three fundamental concepts. The first is the importance in battle of an army's command system, that is the way in which its headquarters is organized. Orders from HQ's are represented by impulse counters. The second fundamental concept is that of "fighting power". Each unit has a total fighting power factor. In combat opposing forces compare their total fighting power factors - the unit with the higher fighting power factor is the victor. Thirdly, every combat unit can move an unlimited distance. However, the further a unit moves in one go, the lower its fighting power will fall. This represents the breakdown of cohesion in a unit if it is pushed too far, too quickly.