Fallout 4 Endings

Unlike previous games, the Fallout 4 ending cutscene does not change based on how the Sole Survivor has finished most quests or interacted with other people. Only the choice of completing Nuclear Family or The Nuclear Option has any effect on the ending. Also, unlike previous games, the ending is voiced by the Sole Survivor instead of Ron Perlman, and unlike the intro - it is based on the chosen gender.

Ending
Part 1: Part 2: Part 3: Part 4: Part 5:
 * Video scene 1-3 - Based on choosing to complete Nuclear Family or The Nuclear Option. In the latter case, it's also based on the gender of the Sole Survivor (One will always be included).
 * Video scene 4 - Always included.
 * Video scene 5 - Always included.
 * Video scene 6 - Always included.
 * Video scene 7-8 - Based on the gender of the Sole Survivor (One will always be included).

Video scenes
Due to the limited variables affecting the ending cutscene, the cutscene itself is not broken down into segments like in Fallout 3 or Fallout: New Vegas; but exist as 4 separate, complete videos for the two endings and two genders. To maintain the format, "scenes" will be used instead of "segments".

Faction endings
Although there are two real endings (Nuclear Option and Nuclear Family) as far as cutscenes are concerned, there are four major endings (one for each faction) and their variants (though there are no cutscenes or ending slides for them). Most notable effects of the ending are what faction patrols the Commonwealth and whose flags appear in Diamond City. And while there are no ending slides which tell the player the future, Mama Murphy can give the player the vision of the future once they choose their side (as part of the quest The Sight)

The Minutemen ending
This ending can only be achieved if the player got into hostile relations with the Institute. In this ending, the Minutemen become the dominant force in the Commonwealth and the player restored the Minutemen to their full power. It is possible to stay on positive terms with the Railroad and Brotherhood of Steel by not making any of those two factions hostile

Variations

 * Minutemen destroy the Brotherhood of Steel - should the player become hostile with the Brotherhood of Steel, be it before or after the end of the Main Quest, they can destroy the Commonwealth chapter of the Brotherhood of Steel with use of artillery and then fighting off the retaliation force
 * Minutemen and Railroad become enemies - should the player not trigger the evacuation signal before destroying the Institute and then speak to Desdemona, the Railroad will become hostile to the player (there are claims that the player can get Tactical Thinking if the Brotherhood of Steel still exists and they didn't get the quest earlier)
 * Minutemen, Railroad and Brotherhood coexist should the player not allow themself to participate in any turning point missions which would make them enemies with another faction (Tactical Thinking from the Brotherhood, or Underground Undercover for the Railroad while starting Mass Fusion for the Institute, which happens before having to betray one of those factions). They rather get banished from the Institute by themself, and then trigger the evacuation signal before eventually destroying the Institute with the Minutemen.

Brotherhood of Steel ending
In this ending, the Brotherhood of Steel destroys The Railroad and The Institute and the Sole Survivor is promoted to the position of Sentinel. Even though their missions has been accomplished, the Brotherhood does not leave the Commonwealth and continue with their other tasks.

Variations

 * Brotherhood and the Minutemen allied - with the Brotherhood's new Sentinel being none other but the Minutemen General, the two factions are technically in alliance
 * Brotherhood of Steel gets betrayed and destroyed by the Minutemen - should the player become hostile to the Brotherhood after the Main Quest is completed, the player can ask the Minutemen to help them destroy the Brotherhood, just like in the Minutemen ending

The Railroad ending
In this ending, the Railroad destroys the Brotherhood of Steel and The Institute, after which their organization starts focusing on protecting the Synths from groups which persecute them. Furthermore, their military presence seems to grow as their agents patrol the wastelands and they also put up their flags around Diamond City.

Variations

 * Railroad ally with the Minutemen - if the player gets banned from the Institute, the Railroad will tell them to ask the Minutemen for help instead, leading to an alliance between these two factions and to the Minutemen ending

The Institute ending
In this ending, the Railroad and the Brotherhood of Steel are destroyed. With their enemies gone and their improved Nuclear Reactor activated, the Institute cements its dominance over the Commonwealth and becomes even more assertive, with numerous Synths patrolling the Commonwealth and the Diamond City being decorated with the flags of the Institute. The Sole Survivor is promoted to the position of the Director and declares their standing on the future of the Institute and the Commonwealth (although it does not have in-game consequences other than their speech repeating on Diamond City Radio)

Variations

 * Institute and Minutemen are at war - If the Sole Survivor used The Railroad to destroy the Brotherhood of Steel, then betrayed The Railroad in favor of The Institute and kill important named NPCs inside (such as Father) before completing Nuclear Family, he will be teleported outside by an angry scientist and the quest The Nuclear Option will be given by Preston Garvey.
 * Institute and Minutemen have questionable relations - if during quest Pinned the player failed to convince the Minutemen to stand down then they will be forced to kill them (or side with them, but that will lock the player out of the Institute ending)
 * Institute and Minutemen allied - although it does not have a direct effect on the game world, the player can tell the Minutemen that they are now allied with the Institute during the quest Pinned
 * Publick Occurrences spreads pro-Institute propaganda - the formerly anti-Institute newspapers release a pro-Institute article if the player sides with the Institute and has a high affinity with Piper Wright
 * The Sole Survivor is in war with Institute - If the Sole Survivor never accepted to be the leader of the Minutemen, used The Railroad to destroy the Brotherhood, then betrayed The Railroad in favor of The Institute and kill important named NPCs inside (such as Father) before completing Nuclear Family, he will be teleportated outside by an angry scientist and the Institute will shoot him on sight.