Over Duke Nukem Forever kun je een complete bibliotheek vol schrijven, helaas zal er geen boek tussen zitten dat de gameplay beschrijft, want het spel zelf is nog in geen velden of wegen te bekennen. Op het 3DRealms forum heeft iemand een tijdslijn van de ontwikkeling van Duke Nukem Forever in elkaar gezet. Het spel is zonder twijfel een van de langst in ontwikkeling zijnde games allertijden, want 3DRealms begon al in januari van 1997 met de nieuwe Duke Nukem titel.Janurary 1997: Work on DNF started.*

April 1997: Quake 2 engine purchase announced. (they got it in mid-late 1997 before Quake 2 was released). Scott Miller states that he is confident that DNF will be released by mid 1998 and prey in late 1998 making 1998 a bit year for 3DR. He also mentions that his confidence is not misplaced.

August and September 1997: First screenshots in PC gamer (hummer, farmer i think).

May 1998: First DNF E3 video shown. You can see that a lot of work has been done.

Late 1998: 3DR announces switch to Unreal tech. It is expected to take no longer than 6 weeks and 3DRealms says "DNF is a 1999 game."

Mid 1999: 3DR admits that the engine switch took a lot more time than originally estimated.

Late 1999: 3DR announces upgrade to UT level tech. It is expected to take two weeks. 3DR releases a Christmas card saying that DNF will be released in 2000.

Unknown 2001: Broussard states that DNF will definitely be out before Unreal 2.

Unknown 2002: Broussard states that DNF will definitely be out before DooM 3.