The 1975 novel that Shogun is based on, also called Shogun, details the rise of a fictional Daimyo Toranaga over many years, as he rises in power to become the military leader of a Japan united under his rule. The story is told from the perspective of a foreign sailor.
The game allows players to assume the role of Toranaga or one of his rivals and assist them in becoming Shogun. This is done by walking through areas and finding ways of drawing others to the player character's cause, or simply eliminating them if the former path is not an option. It was developed by Virgin Interactive for many home systems, such as the Commodore 64.
In 1988 the game was reworked by Japanese company Hect to more closely resemble a Zelda-like top-down view (opposed to the original's side-scrolling perspective) and was drastically changed graphically. The goal and general gameplay remain the same, however. This version was released on the NES.