The game is set within a post-apocalyptic open world environment that encompasses a scaled region consisting of the ruins of Washington, D.C., and much of the countryside to the north and west of it in Maryland and Virginia, collectively referred to as the Capital Wasteland.

It takes place within Fallout's usual setting of a world that deviated into an alternate timeline thanks to atomic age technology, which eventually led to its devastation by a nuclear apocalypse in the year 2077 (referred to as the Great War), caused by a major international conflict between the United States and China over natural resources.

The game was met with controversy upon release in Australia, for the recreational drug use and the ability to be addicted to alcohol and other drugs; in India, for cultural and religious sentiments over the mutated cattle in the game being called Brahmin, a varna (class) in Hinduism; and in Japan, where a questline involving the potential detonation of a nuclear bomb in a prominent town was heavily altered.

[5] The device serves as a menu, and allows the player to access items they have acquired, view detailed character statistics and active quests, and look at the map.

Along the way, the Lone Wanderer learns about their father's background from other characters, including residents of the nearby settlement Megaton, radio DJ Three Dog, and scientist Madison Li.

Its leader, President John Henry Eden, wants to inject the purifier with a deadly virus that will kill any mutated organisms who drink the water, including humans.

In response, the Lone Wanderer enlists the help of the Brotherhood of Steel, a military organization that protects the residents of the Capital Wasteland.

Together with the Brotherhood of Steel, the Lone Wanderer retakes the Jefferson Memorial and learns the water purifier needs to be manually activated, or else it will shortly explode.

[11][12] Under the development of Black Isle Studios, Van Buren was to be set in Arizona, Colorado, Nevada, and Utah, and would have included a mixture of real-time and turn-based combat.

"[11] Development on Fallout 3 began in late 2004 with a small team of around 10 people, as most of Bethesda's staff was busy working on The Elder Scrolls IV: Oblivion.

[11][17] This process exemplified Bethesda's decision to foster a more collaborative approach and allow developers to voice their opinions on various aspects of the game.

[8][20] Due to Bethesda's previous oeuvre with high fantasy role-playing games, some players questioned whether Fallout 3 would simply be an iteration of The Elder Scrolls IV: Oblivion.

[11] Burgess claims a proper test could have yielded a different result, and describes the entire Washington, D.C. area as "the big mistake I feel I made on [Fallout 3]".

[28] For years, there was little new information about the game, although Tor Thorsen of GameSpot notes that interest in Fallout 3 rose significantly after the critical success of The Elder Scrolls IV: Oblivion.

[30][31] The trailer zooms out from inside a bus to show the ruins of Washington, D.C., accompanied by the song "I Don't Want to Set the World on Fire" by the Ink Spots.

[37] Excess blood and gore were removed from the German version by the Federal Department for Media Harmful to Young Persons,[41] and Microsoft chose not to release Fallout 3 in India due to perceived "cultural sensitivities.

[50][51][52] The Xbox 360 version is tied with Braid, Gears of War 2, and Super Smash Bros. Brawl as the fourth highest rated game from 2008 on Metacritic.

"[7] In a review of the game for Kotaku, Mike Fahey commented: "While Inon Zur's score is filled with epic goodness, the real stars of Fallout 3's music are the vintage songs from the 1940s.

Chris Avellone, Fallout 2's main writer, described the game as having "enough options and tools at [his] disposal to insure [he] was having fun no matter what the challenges", praising the immersion in Fallout's world, the success in carrying on the legacy of the previous two games, and the fulfilling open-world component; he criticized the writing of some characters and some of gameplay's choices in balancing the skills of the player character.

[64][67] Edge stated that "the game is cumbersome in design and frequently incompetent in the details of execution", taking particular issue with the nakedness of the HUD, the clarity of the menu interface, and that the smaller problems are carried over from Oblivion.

[71][72] Criticisms include the prevalence of unspoiled food after 200 years, the survival of wood-framed dwellings following a nuclear blast, and the ubiquity of Super Mutants at early levels in the game.

[72][73][74] In response, James Stephanie Sterling of Destructoid called fan groups like No Mutants Allowed "selfish" and "arrogant", stating that a new audience deserves a chance to play a Fallout game; and that if the series had stayed the way it was back in 1997, new titles would never have been made and brought to market.

[68] Luke Winkie of Kotaku tempers these sentiments, saying that it is a matter of ownership; and that in the case of Fallout 3, hardcore fans of the original series witnessed their favorite games become transformed into something else.

The way Fallout 3 strode out, blinked beneath an unfamiliar sun and went on to thrive, genuinely made it one of the greatest experiences of this generation.

"[99] IGN gave similar commentary, and stated, "It's a truly special western role-playing game, one with a deep, post-apocalyptic plot, memorable characters, and an emphasis on choice".

[99][103][104] Its portrayal of 1950s American culture contrasted by the devastation of nuclear war helped Fallout 3 stand apart from contemporary high fantasy role-playing games like The Elder Scrolls and Gothic.

[99][105] Journalists have also noted how the map emphasized exploration, and allowed players to find unique side quests and scenes of environmental storytelling.

[99][106] Khee Hoon Chan of Rock Paper Shotgun remarked, "The Fallout 3 world is probably better traversed when you abandon all pretense of trying to find your father, and wander about the endless wilderness as a roaming wayfarer, discovering these vignettes of humanity's perseverance after a global catastrophe.

"[106] Jeremy Peel of PCGamesN argues that Fallout 3's depiction of Washington, D.C. revolutionized video game exploration due to its non-linear design.

[108] In response to the backlash, journalist Jade King wrote, "It feels elitist to suddenly pigeonhole it as some sort of failure ... Back in 2008, Fallout 3 set a new benchmark for what open world [role-playing games] were capable of.