An Undisciplined unit cannot be put into a simple formation. Usually, the different formations squads can be in are Skirmish, Box, Line, Sparse Line, and Double Line; Undisciplined units can only be in the Skirmish formation. The Skirmish formation spreads units out in a checkerboard pattern, which may be useful in that it reduces the effectiveness of wide-AOE Magic, but it also reduces the Morale of those in the formation by 1.

More importantly, Undisciplined units cannot be given orders. Squads without Undisciplined units can be issued a general command before battle, such as who to attack, whether to favor melee or missile combat, and/or when to start engaging the enemy. Squads with even one Undisciplined unit cannot be given a directive, and so their members will decide to Attack Closest, immediately moving to the nearest enemy and attacking.

Last-but-not-least, Undisciplined troops are terrible at routing, liable to ignore their Commanders and rush off into a random province. Units take a Morale check to see if they remain in their squad and underneath their Commander, if they and their Commander both rout, and the Undisciplined get -3 to their roll. In most cases, they get a -5 instead, due to their squads being locked in the Skirmish formation; the regular disciplined troops in their squad, also stuck in the formation, only get a -2.

Nidavangr has a commander who can override the Undisciplined trait on troops beneath them; this is the Cub-Mother. This ability does not work on Animals or the Undead.