Fallout endings

Military Base
Prerequisites: Destroy the Military Base.

Cathedral
Prerequisites: Destroy the Cathedral.

Master's victory
Prerequisites: Join the Unity (reveal the location of Vault 13 to the Lieutenant or the Master).

Ending 1
Prerequisites: Destroy the Cathedral first and then destroy the Military Base.


 * The Vault Dweller's memoirs establish this ending as canon

Ending 2
Prerequisites: Destroy the Military Base first and then destroy the Cathedral.

Water pump maintained
Prerequisites: Take the chip, fix the pump.

Dehydration
Prerequisites: Take the water chip, don't fix the pump.

Mutant attack
Prerequisites: Enter Necropolis after 110 days have passed or 30 days after killing all the super mutants at the watershed.


 * The Vault Dweller's memoirs and Fallout 2 establish this ending as canon

Gain control of Boneyard
Prerequisites: This ending is bugged and does not appear in the game.


 * Fallout: New Vegas establishes this ending as canon

Killed by mutants
Prerequisites: Accept the quest to spy on the Cathedral. It is not able to be completed. Some sources indicate this ending might occur if The Master wasn't defeated within 90 days of the game's starting date.

New California Republic
Prerequisites: Aradesh and Tandi are alive.


 * Fallout 2 and Fallout: New Vegas establish this ending as canon

Aradesh grieves Tandi
Prerequisites: Tandi is killed, Aradesh is alive.

Tandi takes over
Prerequisites: Kill Aradesh but not Tandi.

Destroyed by raiders
Prerequisites: Kill Aradesh and Tandi.

Razed by mutants
Prerequisites: Enter Shady Sands after 230 days have passed. Takes precedence over the other endings.

Junktown
In the original write-up of Junktown, the "ending sequence" was reversed from its final incarnation. See the alternate endings for the original versions, which were changed because the marketing department decided at the last minute that the game had to "reward good and punish bad".

Killian takes control
Prerequisites: Kill Gizmo but not Killian.


 * Fallout: New Vegas establishes this ending as canon

Alternate version
[With the background picture being a gallows behind Killian with shadows of dead men hanging from it.]

Gizmo takes control
Prerequisites: Don't kill Gizmo.

Alternate version
[With the background picture showing Junktown as a Reno-like casino with electricity and clean streets free of any drug dealers or riff-raff who might endanger Gizmo's operations.]

Destroyed by mutants
Prerequisites: Ending cut from the game.

Drive mutants away
Prerequisites: Don't kill Rhombus.


 * Fallout 2, Fallout 3, and Fallout: New Vegas establish this ending as canon

Dictatorship
Prerequisites: Kill Rhombus.

Traitor
Prerequisites: Ending cut from the game.

Prosperous trade center
Prerequisites: None, many reviews say that the good ending is unobtainable due to something being missing.


 * Fallout 2 and Fallout: New Vegas confirm that this ending is canon.

Abandoned
Prerequisites: Do not complete the quest "Find the missing caravans", or complete at least one quest from Decker, or the Master and the Lieutenant are alive after 140 days have passed.

Destroyed as a fighting force
Prerequisites: Kill Garl and at least eight more raiders, or kill at least thirteen raiders.


 * Fallout 2 and Fallout: New Vegas establish this ending as canon (although a single Khan survivor, Darion, is found from Vault 15 in Fallout 2, where he is quite influental).

Regroup and terrorize
Prerequisites: Enter the raider camp but don't kill enough raiders for the previous ending.

Scourge that lasts for years
Prerequisites: Don't enter the camp.

Ending 1
Prerequisites: Take the Bloody Mess trait when creating your character, or procure bad Karma by the end of the game.

This is also attainable if you very quickly initiate combat upon exiting the conversation with the Overseer. You can kill him and he dies the same horrible fashion as if you have the Bloody Mess trait.

Ending 2
Prerequisites: Don't take the Bloody Mess trait or procure neutral to good Karma.