The second full expansion pack to The Elder Scrolls IV: Oblivion, The Shivering Isles allows players to explore The Isles of Mania and Dementia. Players will be able to reach the Shivering Isles through a door on an island that appears in Niben Bay near Bravil. The expansion will extend Oblivion's gameplay for another 30+ hours, and includes new quests, creatures, and dungeons. Among the new monsters are the Gatekeeper, a collection of bodyparts that have been stitched together, and the Knights of the Order, made up of tree roots.

The retail version of this expansion pack (which was put to disc after the content was originally released for download on Xbox Live) allows gamers to play the award-winning expansion to the 2006 Game of the Year, The Elder Scrolls IV: Oblivion, without accessing Xbox Live online entertainment network. The retail disc also includes the previously released The Elder Scrolls IV: Knights of the Nine.