Infantry form in ranks and files and change formation by left/right face or on a guidon base.
How it works
A rank may not exceed or be started before the one in front is full. Formation change by facing 90 degrees, or by guidon: one base stays fixed and others form left, right or rear, with the footprint shifting no more than 2 files either side. Artillery is limbered (one limber base) or unlimbered abreast. Three or more ranks make a dense target.
When changing formation by guidon, the footprint of a unit may not expand or contract more than 2BW to the left and/or right.