From publisher blurb:
Tomorrow you will bring the battle to the foe. Tonight you walk among the troops you’ll lead. The mercenaries are veterans and sleep while they can, but the peasants levied from your lands seek courage in tales of your previous victories. In the cover of darkness, you can listen rather than lead. Remember when you were like them? Back when you first entered the dungeon, you wielded a sword to fight for gold, glory, and the favor of the gods. Winning these earned you a throne. Now you wield an army, and fight for the right to rule the domains at war.
Domains at War: Campaigns (D@W) is a supplement for Autarch’s best-selling Adventure Conqueror King System (ACKS). Using the rules herein, your fantasy RPG characters can raise armies, campaign against enemy forces, and conquer domains. It includes a comprehensive campaign toolkit for use in ongoing games, fully compatible with ACKS's rules for mercenaries, strongholds, magic, and rulership. D@W: Campaigns also includes a streamlined system for resolving the outcome of pitched battles between army-sized forces, ideal for resolving battles between NPC commanders, where the adventurers are bystanders or front-line participants.
Domains at War: Campaigns is compatible with any fantasy RPG system that uses twenty-sided dice and shares concepts like hit points and armor class. If your players are ready to rule, then your campaign is ready for the Domains at War: Campaigns rules.