Name all of them i can join. i wanna join all of em if i can lol
Thank you sir :)
They're factions, not guilds for the record. And you can't really join the Enclave so much as help them. You can also join the Kings
Brotherhood of steel - you need to do your companion mission first
Ceasar Legion - right when you meet Ceasar himself (story related)
NCR - through the ambassador of NCR (story related)
Yes Man - his the robot that answer everything about the chip (Independent faction/ story related)
Enclave - not sure about this one, but i think you can join after you do the companion mission first
Boomer - located in Airflied, you have to do three of the mission first or all of them you want (independent faction)
House - aka MR. House (indepedent faction/story related).
i think that all of them.
Also I suggest you make a save before joining a faction because you can't join them all in one playthrought because their are certain missions you have to do that will tick off another faction.
Yes Man !!!