The game’s Story and Free modes proceed through two alternating phases: Strategy and Action. In the Strategy phase you can view the entire battlefield, choose which bodyguard to take into battle, and plot movements. If you enter enemy territory, the game proceeds to the combat of the Action phase.
The battlefield map for each stage is divided into a grid of smaller spaces representing bases, main camps, and allied and enemy ground. Map spaces can also represent new tactical opportunities such as gates that block the player's path, and levees that can release a flood.
The types of map spaces and your ability affect the number of spaces you can move at once. After each action phase mission, you’ll receive a score of A, B, or C (with A being the best). A score of “A” allows you to advance up to three squares deep into enemy territory during the Strategy phase, but doing so also increases the difficulty of the proceeding battle.
Some battlefield spaces hold items called “Charms.” Charms are used during the Strategy phase, and they can boost health or strength, attack enemies, open gates or alter the battlefield in ways that are beneficial. Charms have different effects and come in different shapes and sizes, so larger charms affect more map spaces.
You acquire charms when a space where a charm is hidden is cleared, but only a few charms can be held at one time, thus encouraging you to use charms often. Hidden within the map are other items, including weapons, fighting skills, and gold. Enemies will also drop valuable items, such as gold and weapons
Characters will power up incrementally with every 50th enemy K.O., so you will feel your character growing stronger during each battle.
Unlike the Samurai Warriors games for PS2, Samurai Warriors: State of War doesn't use the "Skill Points" system – instead, to learn new techniques, the player must find "Skill Scrolls" during battle.
Samurai Warriors: State of War offers two unique multiplayer challenges for up to four players. After choosing a warrior and subofficers, all players enter separate versions of the same battlefield, and all player-chosen characters are present on your battlefield, but with your opponents' characters appearing as computer-controlled characters. If a player is slain, he will recover with life gauge at half full.
Challenge #1: Vanguard: The player who defeats five enemy captains first wins. If no player defeats all five captains within the time limit, victory goes to the player with the fewest enemy captains remaining.
Challenge #2: Bandit: Defeated enemies drop valuable items. The first player to collect 10,000 gold wins. If time runs out, victory goes to the player with the most gold.