The Elder Scrolls IV: Oblivion

The Elder Scrolls IV: Oblivion, the fourth game in the Elder Scrolls story, is set within the province of Cyrodiil, the heartland and Imperial capital of Tamriel. Emperor Uriel Septim VII is assassinated in flight from his own palace, but just before he dies he passes on to you the mystic Amulet of Kings. The adventure proper begins with the quest to find Uriel's lost and illegitimate son who is the only heir to the throne. In a world where the forces of darkness seek their ultimate dominion over the ranks of man and mer alike, you alone stand between the future of Tamriel and the gates of Oblivion.

The Elder Scrolls IV: Oblivion is a adventure/rpg game available on PC.