When the Ground battle step starts, choose one of your opponent's Ground units with speed 40 or less. That unit gets -2 power until end of turn.
When this unit attacks, the defending unit loses Armor for this attack.
Keywords
Armor
Armor: An isolated, static ability that means, "This unit can only be hit on a roll of 5 or more." Armor works against dice of damage and attack dice. It redefines what die roll is required to hit a unit. It doesn’t modify the die roll like Accuracy. A unit with Accuracy 1 attacking a unit with Armor hits with 4's, 5's, and 6's.