When engaged in combat, Skirmishers do not remain in their usual, dispersed formation. Instead, they will 'form up' into base contact with one another, edge-to-edge and front corner to front corner, against the enemy in order to create a fighting rank. Skirmishers that charge the enemy, or that are themselves charged by the enemy, must always form up in this way once contact is made. Any Skirmishers that cannot make base contact with the enemy cannot form part of the fighting rank and must instead form up into ranks behind the fighting rank.

Skirmishers will maintain this close formation until the combat is over (i.e., until they are not engaged with any enemy at the end of a Combat phase), at which point they will once again adopt Skirmish formation.