There are multiple endings in Fallout 4, though not all of them lead to favorable outcomes. The faction players choose to side with determines the fate of the Commonwealth, so if you're worried about getting the best outcome, you'll need to pick your friends wisely.

Players will have to unlock at least three of the endings in order to unlock all of Fallout 4's achievements, so knowing exactly how to trigger these endings is important for anyone hoping to fully complete the game. Keep in mind that this guide will have spoilers, so anyone that is sensitive to that sort of thing should tread carefully.

Updated May 10, 2024 by Marc Santos: While Fallout 4 has received many updates throughout the years since its launch, none of them made any drastic changes to the base game experience and how the main story's endings are achieved. The following guide contains overviews of all the endings in Fallout 4 based on each of the major factions in the game. It has been updated for better clarity and to help players reach the most optimal ending where both the Railroad and Brotherhood of Steel survive the tail end of the main questline's events.

Minutemen Ending

The Minutemen's main goal is the unification of the Commonwealth. Victory for them means all the settlements in post-apocalyptic Boston will band together and face the future together. This faction is willing to ally with any of the three bigger groups in the Commonwealth, and it's up to you to decide who the Minutemen will support.

This is arguably the best faction to join in Fallout 4 if you want the most number of factions to survive. To reach this ending, you must satisfy the following conditions:

1. Retake the Castle in the Taking Independence quest.
2. Join and befriend the Institute.
3. Become enemies with the Institute by disagreeing with Father or informing the Brotherhood of Steel in the Mass Fusion quest.
4. Speak with Preston Garvey to start the Form Ranks quest.
5. Complete the Defend the Castle quest.
6. Follow the rest of the Minutemen quests.

Doing this leads to the destruction of the Institute and the survival of both the Brotherhood of Steel and Railroad. The settlers of the Commonwealth will unite under the Minutemen's banner, and you'll personally get access to more radiant quests to help rebuild Boston.

Brotherhood of Steel Ending

The path to the Brotherhood of Steel ending begins when players are tasked with building a teleporter to the Institute. A number of optional objectives pop up, giving players the option to tell the other factions in the game about the teleporter. Simply visiting the Brotherhood of Steel after this and alerting Elder Maxson to the situation will suffice.

Continue pursuing the Brotherhood of Steel quests until the option to destroy the Railroad becomes available. Work with the Brotherhood against the Railroad, while also continuing to pursue quests for the Institute. Eventually, the Institute will give the player a quest called "Mass Fusion" — choose to alert the Brotherhood to the Institute's plans, and then this ending will be a sure thing.

There's some pretty shocking story revelations associated with this ending, but overall, it's one of the least desirable ones. It results in the destruction of both the Institute and the Railroad, closing off their quests forever, and killing Brotherhood of Steel members is actually one of the quickest ways to get Power Armor in Fallout 4, so allying with them is not hugely advantageous.

Institute Ending

The Institute ending is one of the easier endings to achieve, as only blatant betrayal of the Institute will knock players off the path to their ending. And even then, some of the possible betrayals along the way will actually be forgiven by Father and the Institute. Though to be on the safe side, just do whatever the Institute says and don't betray their plans to the other factions roaming the Bostonian wasteland of Fallout 4.

The Institute ending results in the destruction of both the Brotherhood of Steel and the Railroad. The implications of the Institute's victory are grim, however, as this faction wants absolutely nothing to do with the people of the wasteland. They will continue to terrorize ordinary people for the sake of their experiments, and no one will be around to stop them.

Railroad Ending

This ending is a bit trickier than the others, as it's possible to get locked out of it if players are kicked out of the Institute too soon. Basically, just stay on the Institute's good side unless outright prompted to act against them by the Railroad. It is during the quest "Underground Undercover" when the Railroad has the player operate as a spy within the Institute, and work against them from the inside.

The Railroad quest has one of the more emotionally satisfying endings, and joining them also leads to easier accces of the Railway Rifle, which is one of the most useful out of all of Fallout 4's weapons.

Just to recap, each ending will see at least two factions obliterated, but the Minutemen will survive regardless of the player's actions. The three endings that are required to unlock all of the achievements/trophies in the game are the Brotherhood of Steel, Institute, and Railroad endings. Since the Minutemen will always be around, players can pursue their quests at any point without worry.

In any case, Fallout 4's multiple endings gives the already massive game added replay value. Whether one is doing research trying to determine what ending is right for them or just trying to beat the game a different way, this guide should offer an idea of what steps need to be taken in order to see all of the endings that Fallout 4 has to offer.