Should you join the Brotherhood or the Railroad in Fallout 4?

Choosing between the Brotherhood of Steel and the Railroad comes down to your personal playstyle and how you feel about synths — both factions are fundamentally at odds, and committing to one will eventually force you to destroy the other.

Here's what each faction offers and demands:

• Brotherhood of Steel is a militaristic, tech-focused organization that views synths as dangerous machines to be destroyed or controlled. Their questline is action-heavy, rewards you with access to advanced power armor and Brotherhood equipment, and culminates in destroying the Institute. However, progressing through their quest Tactical Thinking will lock you out of the Railroad permanently — you'll be ordered to assault Railroad HQ and kill leaders like Desdemona, Glory, and Deacon with no option to warn them or back out.

• The Railroad is a covert underground network dedicated to freeing synths from the Institute. Joining them unlocks Deacon as a companion and rewards you with the Deliverer pistol early on. Their endgame questline has you destroy the Brotherhood's airship, the Prydwen, during Rockets' Red Glare, which means committing to the Railroad ultimately means wiping out the Brotherhood. Along the way, you'll also have to betray the Institute during Underground Undercover.

Key points to keep in mind:

• The Brotherhood and Railroad are mutually hostile — you cannot complete both factions' main questlines. Picking one means killing the other.
• If you want to experience both factions' quests for as long as possible, avoid progressing Tactical Thinking (Brotherhood) or Underground Undercover (Railroad) until you've wrapped up all side content with both groups.
• If synth rights and a more morally gray story appeal to you, the Railroad is the better fit. If you prefer a straightforward military power fantasy with elite gear, go Brotherhood.
• The Minutemen offer a third path that lets you destroy the Institute without requiring you to fully commit against the Brotherhood or Railroad early — worth considering if you want maximum flexibility.

Ultimately, neither faction is objectively "better" — it's about which ending feels right for your character. The Railroad's story is more emotionally driven, while the Brotherhood offers a more structured, combat-forward experience.