This tread and pool are based on spoilers from achievements. We don't know if they are mutual exclusive, but we know that there are three joinable factions:

Minutemen - They seem to be a factions fighting for independence and even their name is based on soldiers who fought against the British during American Revolution, also called Minutemen. We don't know against whom they are fighting, but it is most likely the Institute

Brotherhood of Steel - We don't yet know if they are Lyon's BoS or the Outcasts, but we all know what BoS are ;P Most likely, they are invading the Institute for their advanced technology

Railroad - this faction appeared in FO3 and are abolitionists who free slaves. They are mostly specialized in saving Androids from the Institute

Institute - not a joinable faction, but seem to be the most advanced and ruling faction of Commonwealth... and might be the enemy of the above three factions as well as the prime enemy of the MQ

Well, two of them fight the Commonwealth and BoS will most likely fight them as well. So, what do you think they will be about and whom do you think you will support?

Personally, I think that they will be (and i hope they are) mutualy exclusive and that each faction will try to take over Commonwealth: Minutemen probably want to create an independent state, the Railroad might want to create a state where Androids and humans leave in harmony (or an Android state) while the BoS will want to conquer it for its technology... and maybe add them to their empire, if they used their position at the end of FO3 to take political control over Capital Wasteland.

Whoever has the best access to the type of guns my characters are going to use gets my vote.

i dont know i cant vote w/o knowing.

But yeah i think some factions will be mutually exclusive probably, if not why the player was fight BoS.

With regards to which factions we can join and how they affect each other, I created http://www.gamesas.com/topic/1541450-factions-and-storyline-spoilers thread a few days ago. Hope this helps

Dammit, I was hoping the Institute would be joinable. >:[

Fine. If I HAD to choose just one, I suppose I'll pick the Brotherhood of Steel. The Minutemen and the Railroad have the stench of an alliance to this Khajiit.

If they were joinable, I'd have to put more thought in whom to join. Right now, BoS seems most interesting to me as both Minutemen and Railroad are rebels and rebel factions don't interest me too much (not to mention that BoS is cool XP ).

Institute might end up being evil, but a bunch of British men drinking tea, producing high-tech technology and creating androids sounds cool. If I could support Mr. House in NV, I could support these guys too.

Well, people modded Enclave into FO3. No doubt someone will mod Institute to be playable eventually...

BOS fo life!

If there is no Institute I won't join anyone. I don't like them. Railroad are nasty that prefer aid machines than real people that is being slaved in their home. Brothers of lions are pathetic and goodie goodie. And minutemen I am evil in game I don't care about them at all. So i hope at least could wipe the 3 loosers from The commonwell.

Mutually exclusive factions in conflict with one another are better because this enhances the replay value. Even if they are not exclusive, I'd probably join only one or two factions and try to save the rest of that content for future playthroughs.

For me this kind of role playing game is about choosing to do whatever you think your character would want to do. More fun when the choices have higher stakes and you have to ponder it a bit.

According to Steam store page description:

I'd like to see factions handled more like they are in TES where there are multiple joinable factions each with their own storylines (not just in relation to the main quest) but I don't expect this to be the case

Really? I thought for sure the institute would be a faction you could join, that's a shame. Seems like they'll be the enclave from 3 while minutemen and the railroad are Lyon's BOS #2 and #3 respectively.

I'll probably do it the Yes Man way and take over everything for myself.

If it is the Lyon's CWBoS, side with them unless they think Androids aren't people. Probably the Railroad, then.

If there is a strong independence theme from the Minutemen, would heavily consider.

The BoS.

Hail the Steel Empire led by King Arthur Maxson, whose destiny it is to conquer all of (New) England!

The fact that the Institute isn't joinable (although I don't know what source this is from) make me very sad. I would prefer a more New Vegas style of main quest where anything goes, or at least where one can fight for any faction. Unless there is a really good reason that the Institute doesn't allow recruits or people on their premises, I'm going to be sorely disappointed.

I would hope it is similar to New Vegas as well, in which all of the factions conflict against one another and you're going to have to choose a side, or none at all even.

As for these supposed factions so far, I can't really say, as I haven't got to know them that well. We only know very little about the Railroad from one character in FO3, no nothing about the intentions of the Minutemen (although no doubt they're something along the lines of "FREEDOM HERP A DERP"), and we do not know what chapter of the BoS we're dealing with, and if it is Lyons chapter, how much they've changed since FO3.

The go it alone option sounds the most appealing as of right now.

The source are the achievements. The mentioned three have achievements in same style as Skyrim factions and guilds.

However, we don't know much about the MQ which probably revolves around them. It might be possible that, while we may not join them, we can somehow side with them. Actually, there seem to be two "Silver" achievements (the only gold one is for end of the game/MQ) so maybe the MQ branches out near the end (some achievements do look like they might be Institute-side... though they also might be for something else).

Alright this is very interesting. I hadn't read any of the achievements so I was unaware of this. But looks like we'll see in like 10 days, or a couple more until someone beats the main quest/gets to the point where the institute can or cannot be joined.

I looked over the http://fallout.wikia.com/wiki/Fallout_4_achievements_and_trophies a bit more. If the three factions are part of the MQ, then the MQ branches in five routes after the...

Okay, this is shaping up very well then. Hopefully this is true.

One of the achievements mentions betrayal which I see as a hint that we will probably be joining opposing factions and have to make a choice....also a cool view of the BoS ship going up in flames in front of our player in one of the trailers kind of points to that too. Sort of the way Obsidian handled the issue in New Vegas I suspect. Also the way the game is a 400+ hour game likely means the faction system is free for all to a point.

Are we sure that it is a BoS ship though? I don't remember BoS having those (but they might have found something in Capital Wasteland). I always thought that the airships belonged to the more advanced Institute.

As for Betrayal, it looks like it might just be a quest where a schism occurs in the BoS. It would be neat if we can pick up a side even there, but maybe that would be me being too optimistic...

Tactics and the logo on the ship.

Oh yeah....you see the BoS sign on the burning thing very up close and personal....in the Atom Bomb Baby trailer I think.

Edit: Here: https://www.youtube.com/watch?v=2uBAKPE8ZW0Pause at the 2:00 mark and look to the right....you see the name of the ship PRYDWEN and right next to it the sign of Lyons BoS.

My 1st character will join the Minutemen, then 2nd will join Railroad, 3rd will join Institute.

I'm hoping there will be more factions to join that arent part of the story or anything. If there are more (and even if there isnt), then the 4 story ones should be mutually exclusive.

I'll widly speculate that the railroad opposes the Institute(obviously that's not the wild part) but they'll be indifferent to both the Brotherhood and The Minutemen. The Minutemen I surmise will oppose the Institutes control over the Boston area and want them eliminated for a free and Independent Boston. The Brotherhood will be seeking to annex the territory to either harvest the technology of the Institute, bring Boston into some larger government that's sprung up around DC and the Purifier (or both). The two factions will be in opposition because they have different ideas over whats best for the people of Boston.

What would be nice in this scenario is it peace could me made between them. You could convince the Brotherhood that enforcing there rule on the Boston area would make them no better then the Enclave so that after they take much of the Institutes technology they leave peacefully. Or you could convince the Minutemen that Brotherhood of Steel can provide stability and expertise to improve the lives of the people of Boston. Or you could annihilate one side so the other rules supreme.

Kinda like the cut ending from NV where you could negotiate for the NCR to take control of Hooverdam but leave House in charge of the Strip as its legal owner.

While Android technology might fascinate the Brotherhood that doesn't mean they'd have interested in enslaving fully sentient and sapient machines so the Railroad doesn't care about the fight between the Minutemen and the Brotherhood they only care about freeing the enslaved Androids