Nobunaga's Ambition is set in 16th century Japan during its Sengoku period. The nation is divided into numerous feudal states, ruled by daimyos who often go to war with each other. Many dream of conquering the land and becoming the Shogun, ruling the entire country. Players take on the role of Nobunaga Oda or one of many other daimyos to try to conquer Japan.
The gameplay in Nobunaga's Ambition is similar to that of Koei's Romance of the Three Kingdoms game. Players begin by selecting a scenario, either a 17 region scenario or a larger 50 scenario. They then select a daimyo, each with attributes such as Age, Health, Ambition, Luck, Charm and IQ. As the game progresses, these values change depending on events in the game.
During each turn, players can issue one of several commands from a menu, including recruiting new soldiers, training the army, buying weapons, increasing peasant morale, forming alliances, or hiring ninjas to bribe and assassinate enemies. When one player attacks another, there is a war fought over the defender's region. Battles are fought in an overhead-view hex battle map, with each player taking turns moving units and issuing orders, such as attack, move, bribe, or surrender.