So I'm getting to the pointy end of first play through of aligning with a faction my plan is to make a save at the last point then play each one as I have done this on other fallouts and like to play through their stories/endings. Then depending on circumstances either going back to that last save so I can use all the benefits of each faction eg vertibirds and synth nades. Or go with the faction I most prefer. I'm just wondering how far you can get with all the factions before I start destroying alliances and does it give you a warning like it did in nv before you do. I have a guide book so just missions I can do up to will help and if I have to do anything special in certain missions will be a great help thanks in advance

Yes, it will give you a warning, if you are trying to start a quest that will make a faction hostile.

Mass Fusion is one such mission.

For the Institute: I just do Battle for Bunker hill and some other minor quests.

The next big quest is Mass Fusion, which you will have to complete in favor for the Institute, for both the RR and the Institute ending (never done an Institute ending though).

With the BoS, I usually go as far as this:

Complete Liberty Reprimed

Complete Blind Betrayal

You have to complete Mass Fusion and some other quests for the BoS ending (which I haven't done so far)

Railroad - the last main quest I receive and maybe start but not finish, is:

Underground Undercover, you have to finish this one and a couple of other quests, if you want to go for a RR ending.

The Minutemen come back into play for me, after I get banished from the Institute, for the MM ending.

When you get "Mass Fusion" from the Institute, you have the option of informing the BoS instead. That gives you the option of starting the BoS quest "Spoils of War" instead.


You can only pick one or the other quest, not both. Picking the quest of one faction makes you the enemy of the other faction and fails any open quests with them. Becoming enemies with the faction is immediate and automatic; you get a message that says it happened, and that's it.


Mass Fusion / Spoils of War do the same thing; you just shoot at different enemies.

I have found that you can play the Railroad and the Institute right down to the bitter end... when you must choose.
The BoS is gone - they're the first to go - and both the Railroad and the Institute ask you to do it.
I've done it both ways:
The Institute's eradication of the BoS is less personal, with less individual killing, and you get to see Liberty Prime in action (albeit briefly).
The Railroad's BoS takedown is a bit more nasty, more in-your-face, but you come out of it with your own Vertibird.

I found one player character is suited to follow a Minutemen/BoS playthrough, but I started a new guy to do a Railroad/Institute playthrough.
This was to avoid killing those who I liked and who liked me, who put their faith in me and who trusted me, because breaking trust is the most solemn of tragedies and my character will simply not do that.
I'm not going to take out the BoS as a Brotherhood Knight - or worse, Paladin - that's just not going to happen. My integrity would be ruined (understatement).

So my new guy never joined the BoS. Never even spoke with them...
Doesn't know anything about them. It's the only way to do the Railroad and the Institute endings IMO.
And it was still tough - because I 'knew' them all from a previous playthrough! Heheh...
But if the BoS doesn't know you and doesn't like you, it helps.

Having done all four endings, I personally am playing the Railroad forward.
It feels right, and it feels good. The other endings simply felt off, y'know?
The Minuteman ending is okay, but bland. Diamond City gets taken over by a buncha shabbily-dressed cowboys.
And there's peace at all the checkpoints because the Brotherhood, the Railroad and the Minutemen all get along okay.
But for some reason the Railroad ending feels more... realistic to me.
Just my $0.02