Fallout

=== Setting ===
On October 23, 2077, a worldwide nuclear war between the United States and China following a global conflict caused by resource shortages devastated the world and destroyed modern civilization. The events of Fallout take place nearly a century later in 2161, and follow the Vault Dweller, a human born and raised within Vault 13, one of a number of high-tech underground fallout shelters built to protect survivors. Those on the surface live off the salvage of the old world.
Vault 13 is located beneath the mountains of Southern California. The Vault Dweller can explore major settlements including Junktown, which is mired in conflict between local sheriff Killian Darkwater (Richard Dean Anderson) and criminal Gizmo (Jim Cummings); the Hub, a bustling merchant city with job opportunities; and Necropolis, a city founded in the remains of Bakersfield by Ghouls — humans heavily mutated by radiation — who are revealed to be the former inhabitants of Vault 12. The Vault Dweller's journey also brings them into contact with various factions, including the Brotherhood of Steel, a quasi-religious military order devoted to finding and restoring pre-war technology; the Children of the Cathedral, an optimistic religious cult; and an army of virtually immortal humanoids immune to radiation called Super Mutants, led by an amalgamated creature known as "the Master".

Characters

The player controls the Vault Dweller, who is sent into the Wasteland to save their vault. The Vault Dweller can be customized or based on one of three pre-generated characters: Albert Cole, a negotiator and charismatic leader with a legal background; Natalia Dubrovhsky, a talented acrobat and the intelligent and resourceful granddaughter of a Russian diplomat in the pre-War Soviet consulate in Los Angeles; and Max Stone, the largest person in the Vault who is known for his strength, stamina, and lack of intelligence. The three characters present a diplomatic, deceptive, or combative approach to the game, respectively. Although the character can be male or female, the Vault Dweller is canonically male.
The four companions the player can recruit are: Ian, a mercenary guard from Shady Sands; Tycho, a desert ranger; Dogmeat, a tireless loyal dog; and Katja, a member of an organization called the Followers of the Apocalypse. Other major characters include Vault Boy, the mascot of Vault-Tec, the creators of the Vaults; Killian Darkwater, the mayor, sheriff, and shopkeeper of Junktown; and the Master (Jim Cummings and Kath Soucie), leader of the Super Mutants and the main antagonist.

Plot

In Vault 13, the Water Chip, a computer component responsible for the Vault's water recycling and pumping machinery, stops working. With only 150 days before water reserves will run dry, the Vault Overseer (Ken Mars) tasks the Vault Dweller with finding a replacement. Armed with the PIPBoy 2000 and meager equipment, the Vault Dweller leaves Vault 13 for the nearest source of possible help, Vault 15, but finds it abandoned and in ruins. The Vault Dweller then explores the wasteland and locates a replacement chip in the destroyed Vault 12, underneath Necropolis.
The Vault Dweller returns to Vault 13 with the chip and the water system is repaired. However, the Overseer becomes concerned about the mutants reported by the Vault Dweller. Believing the mutations are too widespread and extreme to be a natural occurrence, the Overseer assigns the Vault Dweller a new task: finding and stopping the source of the mutations. Information discovered throughout the wasteland reveals that humans are being captured and turned into Super Mutants by exposure to the Forced Evolutionary Virus (F.E.V.) at the Mariposa Military Base. A majority of the Super Mutants are led by the Lieutenant, an intelligent cybernetically enhanced Super Mutant stationed at the Mariposa Military Base who takes orders from the Master. The Master intends to transform every human into a Super Mutant and establish "unity" on Earth. The Children of the Cathedral are a front created by the Master, who is using them to trick humans into peaceful submission.
To stop the mutations, the Vault Dweller must destroy the vats containing the F.E.V. and kill the Master; the order of the tasks is chosen by the player. The Vault Dweller travels to the Mariposa Military Base to confront the Lieutenant and destroy the vats within the base, preventing the creation of more Super Mutants. To kill the Master, the Vault Dweller travels to the Children's cathedral and locates a prototype Vault beneath it, from which the Master commands his army. The Vault Dweller infiltrates the Vault and can choose to convince the Master that his plan will fail because the Super Mutants are infertile, kill him immediately, or set off an explosion that destroys the cathedral. The Vault Dweller returns to Vault 13 but is denied entry by the Overseer, who fears that they have been changed by their experiences and the tales of their exploits and accomplishments will encourage the inhabitants to abandon the Vault. As such, the Overseer reluctantly exiles the Vault Dweller into the wasteland. Fallout concludes with the legacy of the Vault Dweller's decisions on the societies and people they had encountered.
Additionally, there is an alternate ending if the player chooses to join the Master. This ending has the player character dunked into the F.E.V. at Mariposa and made into a super mutant, who then returns to Vault 13 with the Master's army and massacres its inhabitants as witnessed on security footage.