Sengoku Kantō Sangokushi is a turn-based historical strategy game set during the Sengoku period of the Japanese history. The player can take control of one of the three prominent warlords of the era: Uesugi Kenshin, Hōjō Ujiyasu, or Takeda Shingen. Each warlord initially controls a province with several towns, and tries to win over territory by diplomatic or military means. Every turn the player has a limited amount of moves at his or her disposal; every general has his own options, though some (e.g. marriage) are restricted to the main warlord himself.
Each town has to survive and raise reputation by maintaining an army and keeping the population happy. This is achieved by trading (buying and selling rice), giving money to civilians or soldiers, developing the town, etc. Every general can also strike alliances with rulers of other provinces, sign agreements, and send spies.
When an area controlled by a general is invaded by the enemy, the game switches into a top-down turn-based tactical battle mode. The player positions and navigates soldiers, engaging in automatic battles when the opponents meet on adjacent squares. Castle invasion and defense can be carried out through various means: for example, it is possible to send an assassin to dispose of the enemy general, or assign archers to fend off the invaders from castle walls.