 Thief II was announced during the Electronic Entertainment Expo on May 13 , 1999 , as part of a contract between Looking Glass and Eidos Interactive to release four new games in the Thief series , beginning with Thief Gold . The deal had been signed on May 7 , roughly three months after Thief II entered production . A tech demo of the game , which Bruce Geryk of Games Domain described as " about three rooms with some Mages " , was displayed on the show floor . The demo was used to showcase the updated Dark Engine , which featured support for colored lighting , higher polygon models and larger environments . The team revealed their intention to include more levels with human enemies , and announced a projected release date of spring 2000 . Plans to include a cooperative multiplayer mode were also detailed at the show . IGN 's Jason Bates noted that the Thief II display attracted " a bit of a buzz and a small crowd of dedicated onlookers " . 
