Detachments do not count towards the minimum number of Core Troops choices.

A Detachment's size can range from a minimum of five models (regardless of the unit's normal minimum) to a maximum of half the number of models in their parent unit, rounding down. Eg, 21 Halberdiers may have up to two detachments, each 5-10 men strong.

Detachments cannot have a standard bearer, musician or champion.

Detachments must be deployed simultaneously with their parent unit and within 3" of it.

Detachments are normal units and are completely separate and independent from their parent unit (eg, they can choose to pursue a broken enemy while the parent unit holds its ground; spells and magic items affecting the parent unit do not affect its detachments; etc.).

Detachments never cause Panic in any friendly unit (including other detachments), regardless of their unit strength.

If a character joins a detachment, that detachment will be treated exactly like an independent unit (it will cause Panic in other Empire units if it is broken/fleeing/destroyed, etc.) and will not be able to use any of the detachment special rules for as long as the character stays with it.