Forever stars its titular character, Duke Nukem, and is the fourth game of the main series. Like its predecessor, Duke Nukem 3D, Forever is a first-person shooter and is being directed by George Broussard, one of the creators of the original Duke Nukem game.

The plot of Forever has been presented through released footage and screenshots. 3D Realms released trailers at the 1998 and 2001 E3 conventions and screenshots between those years. However, as Forever has gone through extensive changes since its last trailer, the plot still remains unclear as of 2007.

The game's release date is still uncertain having gone through so much trouble trying to get it on the launch pad. Every time 3D Realms tried to do that, the technology used for creation had become obsolete so they had to start from scratch.

Duke Nukem Forever was officially announced on April 27, 1997 along with the purchase of a license to use the Quake II engine. Original prototype work on the game had begun as early as January. In August and September, the first screenshots of Forever were released in PC Gamer. In its November issue, Scott Miller stated that the intended release date was 1998. However, 3D Realms did not get the Quake II engine code until December of that year.

In June 1998, the 3D Realms team switched to Epic's Unreal Engine. Broussard said that the transition from the Quake to the Unreal engine would take from "a month to 6 weeks" and that Forever would be released in 1999 claiming to be "only the beginning" as in 1999, 3D Realms announced that they had upgraded to the newer version of the Unreal Engine.

In December, they suggested that DNF would be released in 2000 and so on... until March 21, 2006, when 3D Realms CEO Scott Miller stated that Forever was finished and 3D Realms would begin work on a sequel.

Developer-driven computer and video game publisher Gathering of Developers announced today that the company has acquired the PC publishing rights for the highly anticipated Duke Nukem Forever game, but still no word of actually launching the game. Is that great news or what...?