quick question about "joining" the Brotherhood and Minutemen

As far as faction quests and not other voluntary actions like theft and murder:

  • There are no Minutemen quests that will aggro other factions. You need to make enemies with the other factions on your own before the MM take action. You can finish the game through MM quests and still be aligned with all factions except for the Institute.

  • The Brotherhood's quests will first put you in conflict with the Railroad with the quests Tactical Thinking (begins right after Blind Betrayal) and second with the Institute with the quest Spoils of War. Finishing the game through BoS quests will leave you aligned with the MM.

  • You can become banished from the Institute by choosing the wrong dialog options at the end of the Institute quests The Battle of Bunker Hill, *if you have completed optional quest objectives assigned by either the RR or BoS. The Institute's quests will first put you in conflict with the Brotherhood with the quest Mass Fusion and then the Railroad with End of the Line. Finishing the game through Institute quests will leave you aligned with the MM.

  • The Railroad's quests will require you to follow main of Institute's quests, which aggro the BoS as noted above. Finishing the game through the Railroad's version of the quest The Nuclear Option theoretically makes you enemies with the Institute but I don't believe it ever technically flags you as permanently hostile. You can, for example, retain the Institute-aligned companion X6-88 under the right circumstances. Finishing the game through Railroads quests will leave you aligned with the MM.

/r/fo4 Thread