Deadly Shadows is a stealth game developed by Ion Storm Austin rather than Looking Glass Studios, the original developer of the first two Thief games, (albeit with many of the same people, including the same voice actor, Stephen Russell for the lead character, Garrett), and is a relative departure from the first two games in the series. The game is powered by the Unreal Engine used in Deus Ex: Invisible War engine and unlike the original two titles, Deadly Shadows was developed simultaneously for Microsoft Windows and the Xbox.