GCACW Tactics: Flank Attacks
Example 1
Doubleday and Wadsworth appear to have Rodes flanked but the overall flank modifier is +0. Doubleday and Wadsworth's hexes are covered as are hexes A (in Doubleday's ZOC) and C (impassable to Rodes). Hex B is not covered because there is no road from Wadsworth's hex to B (ZOC does not extend across mountains without a road) and Hex D is not covered because the Potomac River (major river without a ford/bridge) blocks ZOC. With only 4 covered hexes no flank modifier is possible. If the Union was able to cover hex B or D with a Union unit or ZOC then a flank modifier would be achieved. This is one of those rare examples in which a defender is opposed by two enemy units in opposite hexes and no flank modifier is attained.
Example 2
Though it appears that Johnson's division is braced for a headlong assault by Hancock, his position is flanked. All six hexes are covered (A, C, and D because they are impassable to Johnson; B and E because they are in Union ZOC and Hancock's hex because it is occupied by a Union unit). The basic modifier is thus +4 and is reduced by the three impassable hexes to +1. In game terms, Johnson's rear is exposed to Caldwell which weakens his position against Hancock's attack.
Example 3
Caldwell's division is potentially trapped in a mountain pass. Hood attacks and all six hexes are covered (A by McLaws' ZOC; B by Hood's ZOC; C and D are impassable to Caldwell; E by Robertson's ZOC). The basic modifier is +4 and is reduced by two impassable hexes to +2. Caldwell is helped by a +3 modifier for the Mountains but if he is disorganized by the attack and stuck, Longstreet could attack again and possibly inflict retreat losses (can you say voluntarily retreat time?). Note that this example assumes Robertson's brigade has at least 1/4 the strength of Caldwell.
Example 4
Stuart is attacked by Buford. All six hexes are covered. Hexes A, B, C and D are impassable to Stuart. Thus, the basic flank modifier is +4 and is reduced to +1. Though there are four impassable hexes, the maximum reduction of the basic flank modifier is -3. However, the final flank modifier is +0. This is because in all cavalry battles, a +1 flank modifier is reduced to +0. Though Stuart is not flanked, if he is forced to retreat through Gamble, his unit will be eliminated. (Retreating through an enemy units causes a loss of 3 MV).
Example 5
Merritt is at the edge of the world here. All six hexes are covered (A and D by Confederate ZOC; B and C by being impassable to Merritt). The basic modifier is +4 and is reduced to +2 by the two impassable hexes. Because it is an all cavalry battle, it is further reduced to +1. Note also that if Merritt is forced to retreat, his unit will take retreat losses since there isn't a road going north or south through the enemy ZOC.
Example 6
Reynolds assaults Pickett whose flank is being harassed by Union cavalry. Hex B and Early are covered by Union ZOC. Pickett's division is 12 MV strong while Gamble and Merritt's brigades each have 2 MV. Individually, Gamble and Merritt are not strong enough to cover a hex, but adjacent units may combine their strength to cover each other's hexes and thus, both hexes are covered. Hex A is only in Merritt's ZOC and is thus not covered. Collectively, 5 hexes are covered (all but A) so the basic flank bonus is +2. Early negates one covered hex reducing the final flank bonus to +1. If Gamble and Merritt were stacked together in Merritt's hex, then all six hexes would be covered and the flank bonus would be +3.
A Final Note on Flank Attacks
When first learning the system, it is tempting to always try to make flank attacks. If both players make it a point to only attack with a flank bonus, the battle can degenerate into two armies chasing each other's tails. Experience dictates that setting up a flank attack is difficult and often requires winning the initiative several times in a row. If the defender gains the initiative before your assault is ready, he can move away, bring up reinforcements to defend his flanks or counter-attack. The subtleties of the system really begin to show when both players begin looking for both flank attacks and low-odds frontal assaults. Over-using flank attacks (or more precisely, attempting to set-up flank attacks too much) can put you at a disadvantage and in the long run, learning the proper balance of when to flank and when not to is one of the system's advanced techniques to be grasped.