There are four possible endings to Fallout 4, and Amazon’s Fallout TV show might have just confirmed which ones are canon.
In Fallout 4, players are the Sole Survivor of Vault 111. They venture out to find their son Shaun but get caught up in deciding the fate of the Commonwealth. At the end of the story, they need to side with one of the four factions, and it seems either Brotherhood of Steel or the Minutemen are canon, judging by hints from the show.
In the show, the Brotherhood of Steel uses airships to attack the New California Republic outpost in Griffith Observatory. The main control ship appears in episode one, and one fan on Fallout’s Reddit spotted a small but significant detail.
It’s called “Prydwen,” which is the same name as the aircraft used in Fallout 4. It means the Brotherhood of Steel must have come out victorious in the game, with the Sole Survivor siding with them or the Minutemen. If you choose the Railroad or the Institute factions in Fallout 4, Prydwen gets destroyed in one of the final battles.
In the first episode, a Brotherhood elder claims they were given intel from the Commonwealth’s BoS. This is another hint that the faction’s group in the area—where Fallout 4 takes place—is alive and well.
This doesn’t confirm which one of the two endings of the game is canon in the Fallout universe, but it narrows it down. It also hints the Institute was destroyed since it happens in both of these endings.
We’ll unlikely know the answer anytime soon because season two seems to be heading to New Vegas rather than the East Coast. But it at least gives us a hint of what we can expect from the show in the future.