fallout 3 takes place in the year 2277, 200 years after a war over resources that ended in nuclear holocaust in 2077. The setting is a post-apocalyptic, retro-future, covering a region that includes Washington, D.C., northeast Virginia and parts of Maryland. The game's landscape includes war-ravaged variants of numerous real-life landmarks such as the White House, the Jefferson and Lincoln Memorials, Arlington National Cemetery and the Washington Monument. The area that the game is set in, known in-game as the Capital Wasteland, holds a number of small settlements of the descendants of survivors from the Great War. Many inhabitants were killed during the nuclear holocaust and the Wasteland is now little more than a barren land nearly devoid of healthy water, food, plant and animal life due to the extreme radiation levels, however there is a small settlement in the north of the Capital Wasteland where plants are overgrowing the area.
The player begins the game inside Vault 101, where s/he believes s/he is originally born, before venturing out into the Capital Wasteland and facing its many dangers. The Capital Wasteland is home to a number of mutated species of creatures such as two-headed cattle called Brahmin, radscorpions, molerats, and mirelurks. Many of these creatures are generally hostile to the player and will attack on sight. The Wasteland and the city proper is home to several hostile groups, including super mutants, feral ghouls, raiders, slavers, mercenaries, and robots. Of note are the various Vaults—underground structures designed as shelters to protect inhabitants from the dangers of nuclear war (and also for more sinister purposes). In the Washington, D.C. area, many of the roads are blocked off with giant piles of rubble. The player can navigate around the city using a system of underground metro tunnels that connect with other locations (loosely based on the real-life Washington Metro).
Because the game takes place following a nuclear war, cultural advancements have stagnated and, as a result, the game contains a 1950s utopian theme as evidenced in-game through posters and billboards with music from the time period.