
The story was based on the life of Western samurai William Adams, though it was embellished with supernatural elements. The project went through a turbulent and prolonged pre-production period, going through multiple revisions until its final version began development in 2014 for PlayStation 4. Nioh began development in 2004 for PlayStation 3 as part of a multimedia project based on an unfinished Akira Kurosawa script. Gameplay revolves around navigating levels and defeating monsters that have infested an area combat revolves around stamina or "Ki" management and different sword stances that are strong or weak against different enemies. Adams pursues the sorcerer Edward Kelley into the final battles of the Sengoku period during Tokugawa Ieyasu's efforts to unify Japan, an effort complicated by the emergence of yōkai that are flourishing in the chaos of war. Set during a fictionalized version of the year 1600, the plot follows the journeys of William Adams, an Irish sailor named after and inspired by the historic William Adams, an Englishman who became a samurai.

A remastered version was released for PlayStation 5 on February 5, 2021. An edition for PlayStation 4 and Windows, containing the game's downloadable content, was released on Novemby Koei Tecmo. It was released for PlayStation 4 in February 2017, and was published by Sony Interactive Entertainment internationally, and by Koei Tecmo in Japan. Nioh ( Japanese: 仁王, Hepburn: Niō, "Two Deva Kings") is an action role-playing video game developed by Team Ninja.
