In the mid-1990s, Urquhart joined forces with Tim Cain and others to produce the opening act of what would be the Fallout franchise, "Fallout: A Post-Nuclear Role Playing Game". Following Fallout's 1997 release, team-structure negotiations between Interplay and Cain collapsed, leading to the departure of several principal designers of the original Fallout. In 1998, Urquhart was given the reins to Interplay's newly-created development division for role-playing games, Black Isle Studios.
Fallout 2 was released later that year, but due to a rushed production schedule, numerous bugs and programming mistakes were discovered by the general public. Although many of these mistakes were the result of an abnormally-compressed production schedule, blame was laid mostly at Urquhart's feet. However, Urquhart and the rest of the Black Isle Studios staff worked diligently to patch many of the mistakes that made it into the release.
The end of Interplay, the beginning of Obsidian
In 2003, Interplay fell into serious financial difficulties. In December, the Black Isle Studios division was closed down, and its staff laid off - Urquhart included. With the help of former Fallout colleagues Chris Avellone, Chris Jones, Darren Monahan, and Chris Parker, Urquhart founded Obsidian Entertainment in Santa Ana, California.