11.16.1 Declaring combats
(replace all with following)
Any face-up land unit can attack when you declare the combat. Land units which are out of supply attack at only half-strength.
Defending units that are out of supply defend with half of their combat factors (regardless of whether face up or face down). However, each defending unit which is out of supply provides the attacker with an additional +1 die roll modifier (add to both attacker and defender die if using split combat rolls).
Background/Purpose: even out of supply units, if face up, can attack. However, the risks of attacking while out of supply are self-evident: if the attack fails to reestablish supply, the unit is now face down and out of supply and extremely vulnerable. However, desparation attacks aimed at reestablishing supply were known to happen. Defending units are definitely weaker when out of supply, and this is true not only when they are face down but when they are face up as well, which the above rule demonstrates.