TUNNEL CRAWLERS

Use this Stratagem in your Charge phase.
Select one Area Terrain feature. Until the
end of the turn, each time a GSC INFANTRY
unit from your army declares a charge
against an enemy unit within that Area
Terrain feature: Enemy units within that
Area Terrain feature cannot fire Overwatch
or Set to Defend. That GSC INFANTRY
unit ignores the effects of the
Difficult Ground trait from that Area
Terrain feature.