all the factions getting along?

[Vavalry]

In the chapter 3 trailer we can see BoS, Railroad, and Insitute forces working together to defend sanctuary from the Gunners, yet as far as I'm aware without downloading mods that allow all the factions to coexist, how am i supposed to have them all get along?

 

[MisterKen]

Depends entirely on how you play and when you play those portions of SS2 and the vanilla game. I was able to time my SS2 moments with maximum faction support during an attack on GNN, etc. Playing only up to a certain quest in each vanilla faction and stopping will keep them in your game until after SS2 Chapter 3's conclusion, at which time you can do what you want. Or just do what you want when you want.

SS2 does not itself provide a way to have all factions live peacefully together. However, they will cooperate to an end that affects all of them and that problem is Gunners. Also, I wouldn't use the trailers as how it all goes down. They're nice. They'll tell a story, but the actual product sorta kinda won't be (and isn't) quite like that.

 

[Breytac]

You don't. You have to finish the main story. Not hard if you speed run it. Basically, just do the main story and ignore any sidequests. Except for two from the Railroad that you get from PAM which gives you the ability to make ballistic weave for your clothing.

Or you can do the SS2 story alongside the main story, but it will take longer to complete the main story if you do so. As I have all the dlc's, I can do the main story, then start a dlc while also doing to the SS2 storyline.