The add-on does not introduce any new enemies, weapons, or sprites, but it features an all-new episode comprised of ten original levels, each based on a famous location in Washington, D.C. The new levels were created by the winner of the Total Entertainment Network's contest to develop the best independently designed and produced levels for Duke Nukem 3D.
- Hell to the Chief
- Memorial Service
- Nuked Files
- Smithsonian Terror
- Capitol Punishment
- Metro Mayhem
- Top Secret (Secret Level)
- Brown Water
- Dread October
- Nuke Proof
Aliens have crash-landed into the Capitol Building and have launched a massive invasion of Washington, D.C. Duke Nukem arrives to find that the alien invaders have captured several national monuments and critical government buildings, but in the end, Duke defeats the invading army and rescues the President from the Cycloid Emperor.
Duke It Out In D.C. has received mostly praise from fans of the original Duke Nukem 3D. Considered one of the most popular Duke Nukem add-ons of all time, it has been included in all major compilations, and it has been reimagined in multiple total conversions, including Duke Nukem: Alien Armageddon and Nuclear Showdown.
Negative feedback has largely centered on the puzzle elements and extensive backtracking involved in some of the add-on levels. The extensive backtracking is a consequence of the developers' hyperreal approach to level design, which has solicited similar criticisms as those levied against hyperrealism in film; hyperreal films are often criticized for including long scenes that simply depict characters walking from one point to another, without any plot development. The most hyperreal map of the add-on, Smithsonian Terror, has proven to be the most polarizing among fans. Smithsonian Terror is an impressive, full-scale replica of the Smithsonian American Art Museum and is the largest map of the game. However, it also features the most convoluted layout of any level in the game, which most players find confusing during their first playthrough.
Critics have sometimes compared Duke It Out In D.C. negatively to Duke Caribbean: Life's A Beach, a later add-on by the same developers. Civvie 11, a popular YouTuber garnering hundreds of thousands of views per video, published a 20-minute video titled "Pro Nukem 3D: The Rise of Sunstorm" in which he extensively argued that Duke It Out In D.C. fell short of its successor.
Since Duke Nukem 3D: Megaton Edition was removed from the Steam store in 2016, Duke It Out In D.C. has not been available for commercial sale.
Randy Pitchford, the CEO of Gearbox Software, revealed in a May 6, 2020 interview with LoveLaughLeslie that the company was in fact working to package Duke Nukem 3D: 20th Anniversary World Tour with several of the classic expansion packs, including those developed by Sunstorm Interactive. However, Pitchford explained that the project was stalling due to multiple publishing-related problems. Without providing too many details, Pitchford seemed to imply there was a separation of powers between the development studio under Pitchford at Gearbox Software and the publishing house under Steve Gibson at Gearbox Publishing. "I keep putting my thumb on that scale," Pitchford explained, but "this is a publishing project."
According to Pitchford, one problem facing the project, though possibly not the chief problem, was that the publishing team had identified content in the expansions that they considered borderline "sexist and racist." This was news to Pitchford, who said, "it's not exactly the Duke that I remember." For this reason, Gibson was not yet "ready" to move forward with publishing the expansions. Pitchford added, "I don't want to censor it," suggesting the team was considering this as a possible solution. Pitchford further clarified "we stand behind" everything in Duke Nukem 3D and Duke Nukem Forever.
Internet users in the online Duke Nukem community speculated on several possible sources of the borderline "sexist and racist" content in the expansions. These included the portrayal of Caribbean culture in Duke Caribbean: Life's A Beach, the Gorilla Captain in Duke Xtreme, and the Feminist Elven Militia in Duke: Nuclear Winter.
- The downloadable demo of Duke It Out In D.C. includes a number of screenshots; these screenshots are mock-ups in Build, not in-game screenshots, and don't represent real gameplay. This is evident by the presence of locator objects (only found in Build), over-large RPG explosions, the Overlord being in several locations and larger than usual (it is not in this expansion pack at all), and various sprites that are unaffected by sector palette.
- The president in the game, although it's never actually written or told out loud, is obviously Bill Clinton during the years 1993 to 2001 he sat as the United States President. (Though one message on a wall does specifically name 'Bill', referring to a portrait of the president.)
- Charlie Wiederhold created several levels for this add-on. Wiederhold was later hired by 3D Realms to work on the sequel Duke Nukem Forever. He would later join Gearbox Software but leave before they got Duke Nukem Forever.
- One of the levels' names, Dread October, was a parody to the Red October, a fictional submarine which appeared in Tom Clancy's Hunt for Red October and its film adaptation.
- With the DukeDC HRP, NightFright provided a custom soundtrack with music from various sources (e.g. The X-Files, Castlevania, Indiana Jones and the Fate of Atlantis, Robocop 3 or Jill of the Jungle) to fit the atmosphere of the expansion levels. Later on, many players erroneously assumed these tracks were authentic and official part of the addon. However, Duke It Out In D.C. is a replacement of episode 3 (Shrapnel City) and uses its music tracks in the exact same sequence as the original Duke3D episode.
- On April 30, 2017, an all-new custom music pack (Duke DC Music Pack 2.0) was released, composed by James "Jimmy" Paddock in collaboration with NightFright to provide a completely original soundtrack for the addon which captures the atmosphere of the individual levels.
- This add-on has numerous inacessible areas with NPCs hidden in them.
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