Knights of the Nine will also be available as a Windows boxed product at retail on the 21st. The retail version of Knights of the Nine is a compilation that will include all the other Oblivion downloadable content released to date: Horse Armor, The Orrery, Wizard's Tower, Vile Lair, Thieves Den, Mehrunes' Razor, and Spell Tomes. Bethesda Softworks will publish and distribute Knights of the Nine at retail directly in North America and through a co-publisher arrangement with Ubisoft in Europe.

Knights of the Nine features an all-new faction and quests for noble characters and answers many of the questions surrounding the Ayleid ruins found throughout Oblivion. Players can join a new faction and found their own order of holy knights - leading them into battle against a sorcerer-king and his demonic minions while exploring massive dungeons and searching for legendary relics - the holy armor and weapons of the Divine Crusader.

In addition, Bethesda Softworks announced in September that Oblivion will be coming to the PS3 in North America, and that a version for the PSP is also in development for release next year. The PS3 title will contain the Knights of the Nine content.