Template:Special Rule: Allies
Allies. Armies may ally with a wide range of factions in the Heresy supplement, while some are easily incorporated into your force others have a disruptive effect on your overall strategy. Any formations from a “Disruptive” ally reduce the army’s strategy rating by one (-1). Additionally, Supreme Commander rerolls may not be used on “Disruptive” ally formations. Allied force selections must comply with any restrictions within their own army lists. When including formations from an ally army list, the restrictions for Space Craft and Supreme Commanders are applied across the entire force. Only one Supreme Commander can be selected and they must come from the primary army list. For example, an allies line detachment must be purchased before you can purchase an allies support detachment.