Question: Lord of Souls is an English Fantasy novel by Greg Keyes and is the second of two planned books based on "The Elder Scrolls" , a series of action role-playing open world fantasy video games primarily developed by what studios?
Context: The Elder Scrolls V: Skyrim is an open world action role-playing video game developed by Bethesda Game Studios and published by Bethesda Softworks.  It is the fifth main installment in "The Elder Scrolls" series, following "", and was released worldwide for Microsoft Windows, PlayStation 3 and Xbox 360 on November 11, 2011. The Infernal City is an English Fantasy novel by Greg Keyes.  It is the first of two books based on "The Elder Scrolls" series of video games.  It was published on November 24, 2009 by Titan Books in the UK, and Del Rey Books in the US. An Elder Scrolls Legend: Battlespire is an action role-playing open world survival horror video game developed and published by Bethesda Softworks, set in the world of "The Elder Scrolls". "The Elder Scrolls" is an action role-playing open world video game series developed by Bethesda Game Studios and published by Bethesda Softworks.  "The Elder Scrolls" games take place in the fictional world of Nirn, on the continent of Tamriel.  The first game, "", was released in 1994.  It was intended for players to assume the role of an arena combatant, but development shifted the game into a role-playing game (RPG), beginning a tradition that persists throughout the series' history. ""  was published in 1996, and it featured one of the first true 3D worlds on a large scale, with a game world claimed to be the size of Great Britain. "" , released in 2002, saw a return to the old-style expansive and non-linear gameplay, and a shift towards individually detailed landscapes, with a smaller game world than past titles.  The game sold over four million units by mid-2005.  Two expansions were released between 2002 and 2003: "" and "". The Elder Scrolls IV: Oblivion is an action role-playing video game developed by Bethesda Game Studios and published by Bethesda Softworks and the Take-Two Interactive division 2K Games.  It is the fourth installment in "The Elder Scrolls" action fantasy series, following "" and preceding "".  The game was released for Microsoft Windows and Xbox 360 in March 2006, and on PlayStation 3 in March 2007, with a mobile version of the game released on May 2, 2006.  Taking place within the fictional province of Cyrodiil, "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 portal gates to a demonic realm known as "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.  Early in the game, seven skills are selected by the player as major skills for their character, with those remaining termed as minor skills. The Elder Scrolls: Arena is an epic fantasy open world action role-playing video game developed and published by Bethesda Softworks and released in 1994 for MS-DOS.  It is the first game in "The Elder Scrolls" series.  In 2004, a downloadable version of the game was made available free of charge as part of the 10th anniversary of "The Elder Scrolls" series. The Elder Scrolls II: Daggerfall is a fantasy open world action role-playing video game developed and published by Bethesda Softworks and released in 1996 for MS-DOS.  It is a sequel to "" and the second installment in "The Elder Scrolls" series.  On July 9, 2009, Bethesda made "Daggerfall" available as a free, legal download on their website, commemorating the 15th anniversary of "The Elder Scrolls" franchise. The Elder Scrolls is a series of action role-playing open world fantasy video games primarily developed by Bethesda Game Studios and published by Bethesda Softworks.  The series is known for its elaborate and richly detailed open worlds and its focus on free-form gameplay. "" , "" and "" all won Game of the Year awards from multiple outlets.  The series has sold more than 50 million copies worldwide. Lord of Souls is an English Fantasy novel by Greg Keyes.  It is the second of two planned books based on "The Elder Scrolls" series of video games.  It was published on September 27, 2011 by Titan Books in the UK, and by Del Rey Books in the US. The Elder Scrolls III: Morrowind is an open-world, fantasy, action role-playing video game developed by Bethesda Game Studios and published by Bethesda Softworks.  It is the third installment in "The Elder Scrolls" series of games, following "", and preceding "".  It was released in North America in 2002 for Microsoft Windows and Xbox.  The main story takes place on Vvardenfell, an island in the Dunmer province of Morrowind, part of the empire of Tamriel.  The central quests concern the deity Dagoth Ur, housed within the volcanic Red Mountain, who seeks to gain power and break Morrowind free from Imperial reign.  Although primarily a fantasy game, with many game-play elements and Western medieval and fantasy fiction tropes inspired by "Dungeons & Dragons" and previous RPGs, it also features some steampunk elements, and drew considerable inspiration from Middle Eastern art, architecture, and cultures.
Answer: Bethesda Game Studios