Mouri Motonari: Chikai no Sanya (Mōri Motonari: Oath of the Three Arrows) is the third game in the Eiketsuden series. It is a turn based tactical role-playing title that follows the life and conquests of Motonari Mōri, a prominent leader from the Sengoku period of Japan.
Gameplay is similar to the previous titles in the series – each stage has the player deploy a number of officers and equip them with items that improve their abilities. Every stage has at least one objective that must be completed to advance, and a story scene precedes the combat which outlines the events surrounding the battle.
The city areas where the story scenes occur have been expanded to enhance gameplay. After the conversations have ended, the player may control Motonari and explore the city, performing a number of actions including chatting with the populace, purchasing equipment, visiting the temple, or training officers. The training grounds pit an officer against a random opponent, and if the player is victorious, they will earn cash and experience.
Unlike the previous titles in the series, Chikai no Sanya does not have multiple story paths.