is an action role-playing open world video game developed by Bethesda Game Studios and published by Bethesda Softworks and the Take-Two Interactive subsidiary 2K Games. It is the fourth installment in The Elder Scrolls action fantasy video game series, following The Elder Scrolls III: Morrowind. Oblivion was first released in March 2006 for Microsoft Windows and Xbox 360. A PlayStation 3 (PS3) version shipped in March 2007 in North America, and in April 2007 in Europe and Australia. After a number of smaller content releases, a major expansion pack, Shivering Isles, was distributed. The Elder Scrolls IV: Oblivion Game of the Year Edition (a package including both Shivering Isles and the official plug-in Knights of the Nine) was released in September 2007 for Microsoft Windows, Xbox 360, and PlayStation 3, and on Steam in June 2009. A fifth anniversary edition was shipped in North America in July 2011 and in Australia in September 2011. Versions for other regions have been confirmed, although release details are unannounced.
Oblivion's main story revolves around the player character's efforts to thwart a fanatical cult known as the "Mythic Dawn" that plans to open the gates to a realm called "Oblivion". The game continues the open-world tradition of its predecessors by allowing the player to travel anywhere in the game world at any time and to ignore or postpone the main storyline indefinitely. A perpetual objective for players is to improve their character's skills, which are numerical representations of certain abilities. Seven skills are selected early in the game as major skills, with the remainder termed minor. Developers opted for tighter pacing in gameplay and greater plot focus than in past titles.
Development for Oblivion began in 2002, directly after the release of Morrowind. To achieve its goals of designing "cutting-edge graphics", Bethesda used an improved Havok physics engine, high dynamic range lighting, procedural content generation tools that allowed developers to quickly create detailed terrains, and the Radiant A.I. system, which enabled non-player characters (NPCs) to make choices and engage in behaviors more complex than in past titles. The game was developed with fully voiced characters—a first for the series—and features the music of BAFTA-award-winning composer Jeremy Soule. Oblivion was well received and has won a number of industry and publication awards. It was praised for its impressive graphics, expansive game world and schedule-driven NPCs. The game had shipped 1.7 million copies by April 2006, and sold over 3 million copies by January 2007.