To represent their unique way of fighting, detachments may use the following rules, but only if they are within 3" of their parent unit (and not if the parent unit is fleeing or has declared a flee reaction).
Use Parent Unit's Leadership
A detachment in close support (i.e. within 3" of its parent unit) always uses the parent unit's Leadership for any Leadership tests, unless its own Ld is higher (this could happen if the detachment is in range of the General's Leadership while the parent unit isn't, for example).
Support Fire
See Figure 1. In the enemy's movement phase a detachment in close support may stand & shoot against an enemy unit charging its parent unit if the detachment itself has not been charged and is not countercharging in the same turn. A detachment can offer support fire even if the parent unit cannot stand & shoot itself (enemy too close, for example), and does not suffer the -1 to hit penalty for standing & shooting.
Countercharge
See Figure 1. In the enemy's movement phase a detachment in close support may countercharge an enemy unit charging its parent unit if the detachment itself has not been charged. After the enemy has finished moving all its chargers, but before remaining moves, the detachment can declare a normal charge against the enemy. If the detachment can draw a line of sight to an exposed flank of the enemy, and has enough Movement to reach it, it can charge the enemy in the flank, even if it would normally have to charge its front. The detachment will get the normal flank attack combat bonus and will negate the enemy's rank bonus so long as the detachment has a unit strength of at least 5, as normal.
Apart from the exceptions noted above, the countercharge follows all the normal rules for charges (the detachment must pass a Leadership test to charge Fear-causing enemies, it can wheel only once during the move, etc.). In the close combat phase, resolve the countercharging detachment's attacks first, then resolve the attacks of the enemy and finally work out those of the parent unit that was charged.
Supporting Charge
See Figure 2. In its own movement phase a detachment in close support may make a supporting charge by hitting the flank of an enemy unit charged in the front or rear by its parent unit (or indeed hitting the front or rear of an enemy unlucky enough to be charged in the flank by the parent unit). Declare the supporting charge when you declare the charge of the parent unit. If the charge of the parent unit does not hit its target (failed Psychology test, out of range, etc,), the detachment does not charge either, and may not move further nor shoot that turn. After the parent unit has been brought into contact with the target unit and after all other chargers have been moved, but before remaining moves, the detachment is moved into contact with the same target. If the detachment can draw a line of sight to an exposed flank of the target, and has enough Movement to reach it, it can charge the target's flank even if it should have charged its front. The detachment will get the normal flank attack combat bonus and will negate the enemy's rank bonus, so long as it has a unit strength of at least 5. Apart from the exceptions above, the supporting charge follows all the normal rules for charges.
