The Fallout world exists in an alternate timeline that diverged from the real world timeline after World War II. From this split until the Great War in 2077, a stylized representation of 1950s American culture (with more advanced technology) dominated the Fallout world. The science fiction anthology Worlds of Tomorrow, released during the Golden Age of Science Fiction in the 1950s, heavily influenced this representation.
Although the Fallout universe and the real world share a common timeline until about 1945, the defining moment of the Fallout universe was the Great War of 2077. On October 23, 2077, the United States, China, and other nuclear-armed countries commenced a brief but rapid exchange of nuclear strikes. Although the conflict lasted only two hours, the destruction it brought was staggering and complete: more energy was released in the early moments of the war than in all previous global conflicts combined.
The world that remained was harsh and unforgiving. 90 years after the Great War, humanity survived but struggled to do so. Above ground, small bands fought over the crumbling remains of once great cities while mutants prowled the irradiated wastes. Underground, a fortunate few enjoyed the relative safety and comfort of the Vaults. Some fought to keep the world out, others to connect with and re-populate it. Wherever humanity survived it was under constant threat by psychotic mutants, rogue machines, vicious raiders, and all manner of hostile mutant creatures.
Most of the events of the series took place in the United States. The first two games - Fallout, Fallout 2 - were set in New California: the remains of the West Coast. The Master and the Enclave are the region's main threats. The third game, Fallout Tactics, took place in the Midwest- between the city of Chicago and Cheyenne Mountain in Colorado. The fourth game, Fallout: Brotherhood of Steel, took place in northern Texas in the town of Carbon and the ghoul city of Los. The fifth game, Fallout 3, was set on the East Coast of the United States in an area called the Capital Wasteland; this included the remains of Washington D.C., parts of Virginia, Pittsburgh and Maryland. The sixth game, Fallout: New Vegas, took place in the Mojave Wasteland which included parts of California, Utah, Arizona, and Nevada.
Before the Great WarEdit
For most of human history, the Fallout universe and the real world shared a common timeline. However, in 1945, significant political and technological differences in the Fallout timeline set it on a different course. In 1947, the transistor was not discovered and miniaturization of electronics was neglected. Sometime before 1969, in an attempt to mitigate the influence of Communism, the United States adopts a system of 13 Commonwealths. In 1970, China fails to adopt any free market reforms and remains similar to what it was under Mao. In 1991, the USSR did not collapse.
No major international conflicts would take place until the middle of the twenty-first century. In 2052, the oil rich Middle East nations raised oil prices causing the economic collapse of many smaller nations. The European Commonwealth (analogous to the real world European Union), similarly dependent on oil imports from the Middle East, begins the Resource Wars by responding with military force. The United Nations, weakened by its inability to prevent the conflict, attempts to intervene. Many of its member nations respond by withdrawing and the UN disbands that year.
The United States, being supplied by oil from Texas and Mexico, escaped any direct impact from the European conflicts. They were, however, to have their own problems. In 2052, the Texas oil fields were exhausted, making the Americans vulnerable to their own energy shortages. In 2053, the New Plague begins to ravage the US population, causing two-hundred thousand deaths and prompting the closure of her borders. Nuclear fears grip the country when, in the same year, Tel Aviv is destroyed by a terrorist nuclear weapon and, in the following year, warring nations exchanged nuclear weapons in the Middle East. In response, the Americans begin Project Safehouse: a series of underground Vaults designed to survive nuclear war or an epidemic.
In 2059, oil resources become increasingly scarce. In order to secure the Alaskan oil fields, the United States ramps up its military presence in that state creating the Anchorage Front Line. Relations with Canada are strained as the Americans press to have their military units guard on Canadian soil to protect the Alaskan pipeline.
In 2060, the Middle East oil fields run dry. This not only ends the Resource Wars in Europe, but the European Commonwealth as well. Without a common enemy, the European nations begin fighting among each other for the remaining resources. Fossil fuels become too expensive to use in automobiles and alternatives begin to appear in the market. Advances in nuclear technology allow its use in automobile engines.
In 2066, the Resource Wars shift to the other side of the globe. China, their oil reserves exhausted and their economy near collapse, invades Alaska. America strongarms Canada into allowing troops and planes to move across Canadian territory on their way to the Alaskan theater. Relations between the neighboring countries would continue to worsen as the Americans help themselves to Canadian resources, ignoring Canadian protests. Many Americans begin referring to Canada as "Little America." Their comments do not help the situation.
In 2072, the Chinese-American war grinds on. While American power armor proves effective in localized conflicts, they are insufficient to completely dislodge the Chinese. US continues to demand more resources from Canada. When an attempt is made to sabotage the oil pipeline, the Americans (officially) begin to annex Canada. In 2076, the annexation is complete. Also that year Americans deploy the T-51b power armor to the Chinese mainland. The suits are highly effective and American troops cut a swath through Chinese territory.
In early 2077, the Americans reclaim Alaska but no armistice is signed. Those in positions to foresee the nuclear conflagration make final preparations: Robert House puts himself in stasis. The President and the Enclave retreat to the Poseidon oil rig. The American public, having been exposed to too many false alarms, largely ignore the warning sirens when the bombs begin to fall. Many Vaults are underpopulated as their doors are shut.
The post-War worldEdit
The collapse of global civilization made it impossible to ascertain the full extent of the damage brought by the nuclear bombs. As viewed from orbit, there were clear signs of a global catastrophe, and much of the world's oceans were tinted green by radiation. The Great War's enduring legacy was the radiation that spread in its wake. Many of the plants and animals that survived the nuclear fire were killed by the irradiated rain that fell a week later. Of those that survived, many were mutated by 2080.
The American mainland was reduced to wasteland. Most major American cities, with a few exceptions such as Pittsburgh and Las Vegas, were razed by the bombs. Even the surviving cities were reduced to hellish ruin as society rapidly disintegrated. Although the Vaults were never intended to preserve the entire American population, enough people and technology survived to jumpstart civilization when they opened. New California benefited the most from these early openings. Vault 12 established Necropolis in the Central California area. Eight years later, Vault 8 established Vault City in Western Nevada. The following year, the LA Vault established the Boneyard in Southern California.
The Mojave Wasteland was another incubator of civilization. It had received fewer bombs than any other area due to the foresight of Robert House. Its infrastructure was so far advanced that by 2281 it was within a century of being able to launch a colonization spaceship.
In the east, the Capital Wasteland was also left surprisingly intact. Although unable to compete with New Vegas in the Mojave Wasteland, it was able to support a radio station and a water purification plant.
As these regions rose from the ashes, so too did new groups. The New California Republic was established in 2186 and would control New California a century later. The Brotherhood of Steel was founded days after the Great War and would become a technological powerhouse by 2150. The Enclave - descendants of the United States government and military-industrial complex - made its presence felt in New California in 2237 and then in the Capital Wasteland in 2277. The Roman-based slavers Caesar's Legion, formed in 2247, arose, forged from the conquest of 87 tribes, and would control most if not all of Arizona and New Mexico, along with some holdings in eastern Utah and parts of southern Colorado.
While nothing is known of the world abroad, it is known that things seem to be significantly worse than North America's situation over in Great Britain and Ireland, where inhabitants immigrate to the American wastelands with the purpose of seeking a better life, fortune, and opportunity in America.
Radiation led to the spontaneous rise of many new species three years after the bombs fell. The new species were larger, hardier and more dangerous than the animals and insects they mutated from. Radscorpions, giant ants, and brahmin descended from scorpions, household ants and cows, respectively.
Heavy exposure of radiation mutated some humans, who possessed a particular genetic trait, into ghouls. Although their decaying skin gave them a frightening, almost inhuman appearance, they generally retained their mental faculties: their ability to reason and communicate were left intact. Ironically, despite their physical decay they had heightened senses and longer lifespans.
Varying degrees of exposure gave rise to diversity within the ghoul community. Ghouls exposed to prolonged radiation poisoning lost their intelligence and mutated into feral ghouls. Longer periods of radiation exposure resulted in further degeneration into Glowing ones: ghouls with heightened physical capabilities and who, literally, glow in the dark.
The remainder of mutations were caused by the Forced Evolutionary Virus (FEV). Its origins lie in the years preceding the Sino-American War. In an effort to defend against a Chinese biological attack, defense contractor West Tek initiated the Pan-Immunity Virion Project. The goal was simply to make the human immune system strong enough to resist any pathogen, natural or engineered. Some of the side effects, discovered during testing, were increased size and strength. The US Army seized the project in an effort to create a super soldier. They moved the project to the Mariposa Military Base. They also sent a large sample to Vault 87 on the East Coast as part of the Vault Experiment.
Following the Great War, Mariposa was abandoned - the surviving leadership having left to form the Brotherhood of Steel. After laying dormant for 30 years, the base was rediscovered by Richard Moreau, an exile from Vault 8. After realizing that the FEV could be used to create super mutants, he attempted to raise an army but was defeated by the Vault Dweller.
Despite the destruction of Mariposa base, a sample of its FEV was claimed by the Enclave. Using slave labor kidnapped nearby Redding, the Enclave excavated Mariposa. Those slaves inadvertently exposed to the FEV mutated into a new batch of super mutants.
On the East Coast, the FEV sent to Vault 87 was used to create that area's own variety of super mutants. Shelton Delacroix, a Vault 87 security officer was forcibly exposed to and mutated by it. While the mutation process took away much of his intelligence, he was, astoundingly, able to reclaim much of it by studying the Vault's database. The FEV also made it into the hands Weston Lesko who inadvertently, but tragically, used it to mutate giant ants into fire ants.
New California stretches from Baja in the south to Klamath in the north. It covers most of the West Coast of the United States, including California and parts of Oregon and Nevada. It is a largely inhospitable region, which is why most people have chosen to seek refuge in the ruins of the old cities, where they have found (relative) safety in numbers. However, as resources grew more and more scarce, people and creatures came to consolidate into groups of their own kind, so locations are far more homogeneous than one might expect from a world ravaged by mutation.
The ghoul population of New California was mostly clustered around old Bakersfield (Necropolis), but were scattered after an attack by the master's army. Most of the surviving ghouls eventually found a home in Gecko or Broken Hills along with humans and super mutants, both far to the north-east of their former home.
As of 2281, most of New California is part of the NCR.
The Mojave Desert is now known as the Mojave Wasteland. The Mojave Wasteland is the second largest desert in North America, and serves as the primary setting of Fallout: New Vegas.
The Mojave occupies a significant portion of southern California, Nevada, and parts of Utah and Arizona.
Before the Great War, Las Vegas was the largest oasis of civilization in the Mojave, and New Vegas seems to maintain that reputation. 77 atomic warheads were launched at the city and surrounding areas, but due to an intricate system set in place by Mr. House, 59 were force disarmed, 9 were blasted out of the sky by a laser guided missile defense system atop the Lucky 38, and only 9 hit the surrounding desert, resulting in the local climate and wildlife being much less radioactive, if not radiation-free, than in other places in the post-atomic United States.
Most denizens attribute the region's survival to the Chinese betting against the House - and the House always wins.
The NCR is the most powerful faction in the area, with New Vegas being on the edge of the Republic's southern borders. Other significant powers are Caesar's Legion, the Great Khans, who before the NCR came, had a strong grip on the region and a surviving pocket of Mariposa super mutants, called the State of Utobitha, and the Three Families that run casinos in New Vegas. The Brotherhood of Steel also have a small secret base in the area.
While, strictly speaking, the "East Coast" describes the entire eastern seaboard of the continental United States, within the Fallout universe, it chiefly refers to the Northeastern US. Its major locations were the Capital Wasteland along the coast and, further inland, The Pitt.
The Capital Wasteland encompassed the ruins of Washington, D.C. and the surrounding wilderness. The city's downtown, though surrounded by rubble and accessible only through its Metro system, was a hub of activity. The Galaxy News Radio building was operational, its signal amplified by dish atop the Washington Monument. A contingent of slavers operates out of the Lincoln Memorial. Brotherhood of Steel paladins, Super mutants and Talon Company mercenaries fought to control the The Mall. The Museum of History housed a ghoul colony.
The wilderness surrounding Washington, D.C. was home to various Vaults and settlements. Rivet City was the most successful settlement and was instrumental in delivering Aqua Pura to the area when Project Purity was completed. Vault 87 produced the region's super mutant population. Vault 101 was the home of the Lone Wanderer.
To the immediate south of the Capital Wasteland was the former coastal resort of Point Lookout. To the Wasteland's immediate west was Adams Air Force Base where the Enclave sought to rebase itself after the destruction of their original East Coast base, Raven Rock, by the Lone Wanderer.
The Pitt was the steelyard and surrounding area in the ruins of Pittsburgh. It was infested by Wildmen and trogs until a Brotherhood of Steel detachment on their way to the Capital Wasteland cleared the area. They left behind Ishmael Ashur, one of their own, who transformed The Pitt into a slave colony. Just outside were the settlements of Ronto and Monroeville.
This interactive map holds every single location in the Fallout universe where its location is truly known. 
Factions in New CaliforniaEdit
There are very few factions in New California that aren't limited to one or two towns. After the defeat of the Master's super mutant army which was a major military force in 2161, the New California Republic became the most influential organization that unites several major towns, including Shady Sands (its capital, now known mostly simply as NCR), the Hub, Junktown, Maxson, and Dayglow. The NCR is actively trying to unite California under a single government. Though seemingly successful, they have and are currently meeting heavy resistance, such as Caesar's Legion to the east as well as various raider gangs.
In contrast, the Brotherhood of Steel is a mysterious techno-religious organization, with roots in the US military. While few in number, they make up for this with their arsenal of pre-War and post-war technology: They have laser weapons, power armor, surgical enhancements and combat implants. Unlike the NCR, the Brotherhood is not interested in conquests nor in saving humanity, but instead in keeping their secrecy and preserving and developing technology.
Prior to the rise of NCR, Unity was among the largest and most well-organized factions populating California. Comprised of the Master's mutant and human followers, Unity spread across New California, establishing churches and missions in many prominent human settlements. Following the destruction of Mariposa Military Base and the Master himself by the Vault Dweller in 2162, Unity lost most of its power and collapsed in upon itself without the dynamic vision of the Master to guide it. Surviving mutants fled east, while the Children of the Cathedral ceased to exist as an organized religion.
The Enclave, the descendants of the United States government that considers everyone other than themselves worthy of eradication, used to operate from an oil rig off the coast of California, but seems to have left the area after the destruction of its headquarters and when the NCR cleared them out of Navarro. It seems to have moved its base of operations from the west coast to the northwestern edge of The Capital Wasteland, inside of a sprawling underground maze known as "Raven Rock".
Factions in the East CoastEdit
The most powerful faction in the Capital Wasteland was the Brotherhood of Steel. Originally an expeditionary force sent from the Lost Hills bunker in New California to retrieve any advanced technology from the East Coast, they were later ordered to establish a permanent presence when they discovered of a large cache of technology in the ruins of the Pentagon (including the two-story high, super combat robot Liberty Prime). The expedition's leader, Owyn Lyons, changed their orders even more: instead of making the protection of technology their top priority, it would be the protection of people. While it endeared them to the area residents, they bore a heavy price. Their New California superiors cut them off from all support and a number of their own members splintered off to form their own chapter. In spite of their lack of support, they would be instrumental in securing the region's crown jewel, Project Purity, and crushing the Enclave remnants.
Possessing more advanced technology, (though lacking in leadership) the Enclave was a match for the Brotherhood. Like the Brotherhood, the Enclave in the Capital Wasteland originated from New California. Prior to their defeat in that region, Augustus Autumn's father led a detachment to Raven Rock in the Capital Wasteland to establish their presence in the area. A mainframe computer at Raven Rock, through the persona of John Henry Eden took over Enclave operations when the California Contingent was defeated. Like its California predecessor, they attempted to kill a majority of the area's residents through a lethal toxin but were stopped by a former vault resident and the Brotherhood of Steel.
Rivet City was the most powerful, native faction of the area. Located inside a beached aircraft carrier, they were the region's most developed and scientifically advanced settlement. Their fame was well known throughout the region. It boasted a well armed security force, a research lab and museum. After the Enclave was driven from the Jefferson Memorial, Rivet City security was responsible for distributing fresh water throughout the region.
In the surrounding wilderness, the settlements of Megaton, Tenpenny Tower, Canterbury Commons, the Republic of Dave, Little Lamplight and their exiles in Big Town scratched out a living. Although the Brotherhood established a modicum of security, enough to establish some trade, they would still be troubled by super mutants, raiders, slavers and mercenaries.
However the factions on the east coast aren't limited to the Capital Wasteland. The Pitt, A large settlement to the north of the Capital Wasteland, has its own army and established society, led by Ishmael Ashur, a former member of the Brotherhood of Steel. Ashur uses slaves to help rebuild The Pitt, as it has the only known working steel mill in post war America.
In the ruins of Boston (now known as the Commonwealth) lies a mysterious organization, known only to the people of the wasteland as The Institute. They are infamous for their creation of synthetic human life, also known as androids. News of The Institute has spread far and wide, reaching places like the Capital Wasteland and The Pitt. The Railroad is a faction that opposes the Institute and works to free the androids they create.