Both players total the Strength of all the Units, Vessels, and Structures in the Battle:
1. The “Natural Strength” is the value as listed beside the Unit's picture on the Capital City Board, or its card, before bonuses are considered.
2. Add in all ability bonuses of Heroes, Vessels, and Structures that increase Strength. Defenders apply their abilities first, then the attacker.
3. Cast 1 Combat Spell to add Strength to an army, decrease Strength from an enemy army, or destroy enemy Units. The defending player always casts a Combat Spell first. Once defender does so or announces that they are not casting, the attacking player may then cast a Combat Spell.
Then, Select a Tactic Card to Play (see related rule).