Quests

Almost nothing in the Commonwealth is scarce. Caps come back, junk respawns, settlers keep arriving, and the radiant quest boards will hand you work until you stop asking. There is exactly one resource the game will not replenish, and that is your standing with the four factions. Finish one of their questlines and you have permanently destroyed at least one of the others.

That is the only line worth drawing through Fallout 4's quests, and it is the one this guide uses. Everything below is sorted by what the quest closes behind you: nothing at all, itself, or somebody else's entire storyline. If you are trying to work out what is safe to do before you commit, read the first two sections and stop before the third.

Three kinds of quest

Every quest page we have falls into one of three buckets, and the difference between them is not length or difficulty but consequence. A radiant quest costs you an afternoon. A side quest costs you an afternoon and gives you a permanent item. A faction quest can cost you three other endings.

The four lines that cancel each other

The Brotherhood of Steel, the Institute, the Railroad and the Minutemen all want the Commonwealth run their way, and three of the four are willing to kill the others over it. Our factions guide covers who they are; what matters here is that their questlines share endgame beats, so completing a step for one is often the step that makes another impossible.

Brotherhood of Steel

The longest of the four and the one with the clearest arc, running from a distress call at the Cambridge Police Station to Liberty Prime walking into the Institute. Two moments inside it are worth knowing in advance. From Within lets you talk Doctor Li into cooperating with a Charisma check, and succeeding there skips most of Liberty Reprimed's fetch work later. Spoils of War then gives you the choice that decides everything: you can retrieve the Beryllium Agitator for Ingram, or leave and tell the Institute, which switches your loyalty and starts their version of the same mission.

The line also carries the best reward in the game for a single quest. Finishing A New Dawn earns the Sentinel rank and a Power Armor jetpack, and it is the rank that unlocks the Sentinel's Plasmacaster from Proctor Teagan.

The Institute

The shortest main line, and the one that spends the least time convincing you. It opens with Synth Retention and closes with Nuclear Family, and in between it asks you to do to the Railroad and the Brotherhood exactly what they would have done to the Institute. End of the Line kills Desdemona and the Railroad's leadership; Airship Down brings down the Prydwen with a Synth hacking Liberty Prime while you deal with the generators.

Mass Fusion is the mirror of the Brotherhood's Spoils of War, and it works the same way in reverse: relay to the roof and stay loyal, or leave and tell the Brotherhood and switch sides. If you want to see both, this is the quest to save before.

The Railroad

The Railroad is the hardest faction to find and the easiest to lose. Getting in means walking the Freedom Trail from Boston Common through five markers and spelling out RAILROAD on the ring under Old North Church, and our Railroad guide lists every marker in order. From there Underground Undercover requires you to be inside the Institute at the same time, which makes it the most fragile line in the game to hold together.

It also has the only quest that exists to catch you out of position. Burning Cover only appears if your relationship with the Institute turns violent before Underground Undercover, and it exists purely to hand you back to Preston Garvey.

The Minutemen

The Minutemen are the safety net. They have no quest that destroys another faction on their own, they become available if you are thrown out of the Institute, and Form Ranks exists specifically to restart them after everything else has gone wrong. The trade is that their line is mostly infrastructure: build beds and water at Sanctuary, retake the Castle from a Mirelurk Queen in Taking Independence, then build and test artillery in Old Guns.

Old Guns is worth finishing whichever faction you back, because it puts Ronnie Shaw at the Castle and she is the only source of The Last Minute.

One event, two versions

Three of the endgame beats are the same scene written twice, and reading the two guides side by side is the clearest way to see how the branch works. Mass Fusion and Spoils of War are the same trip to the same roof for the same Beryllium Agitator, differing only in who sent you. The Nuclear Option appears under both the Brotherhood and the Railroad, and both versions end in the Institute reactor with a fusion pulse charge. Airship Down and Rockets' Red Glare are both the destruction of the Prydwen, once from inside the Institute and once from a Vertibird.

The practical consequence is that a save made before any of those three is worth keeping, because it is the last point from which more than one ending is still reachable.

The lines that never run out

Each faction also has a radiant board, and these are the opposite of the main lines in every way: infinitely repeatable, individually trivial, and impossible to get wrong. They are how you level, how you gain settlements, and in the Brotherhood's case how you get to the miscellaneous quests that carry real rewards.

The Brotherhood board is the one with real content attached. The Lost Patrol chains four distress signals to Recon Bunker Theta and Paladin Brandis, Duty or Dishonor is a small investigation you can resolve by killing Clarke, turning him in or lying about it, and A Loose End sends you to kill Virgil, with the option to spare him and lie to Kells instead. Feeding the Troops even offers a choice you can buy your way out of: 1,000 caps for the crops, or kill the settlers and farm it yourself.

The Minutemen board is the one that changes your map. Taking Point clears and claims a new settlement, Resettle Refugees only appears once the Institute is destroyed, and Suspected Synth only exists while it still stands, which makes the board itself a rough indicator of how far into the story you are.

DLC lines, which close only themselves

The add-on questlines sit outside the faction war entirely. None of them will cost you an ending, all of them can be done at any point once their entry condition is met, and each one leaves you with something permanent.

Automatron is four quests long and gated on character level rather than story progress. You need to be level 20 before the Caravan Distress Call appears at all, which our Automatron starting guide covers along with what to check if the DLC refuses to launch. From there Mechanical Menace, A New Threat, Headhunting and Restoring Order run to the Mechanist's den, and the recurring hazard throughout is the same: the large robots and the Mr. Handy in the Fort Hagen Satellite Array all explode hard enough to kill you outright, so shoot legs and keep your distance. Headhunting is also where Ivey drops the Tesla armor.

Vault-Tec Workshop is the longest and the least combat-heavy. After Vault-Tec Calling and Better Living Underground open the vault, the rest of the line is a sequence of experiments run on the same template: build a prototype, power it, connect a terminal, assign Clem, pick one of three parameters and wait about an hour. Power to the People, The Watering Hole, Vision of the Future and Lady Luck all work that way. The one thing to know in advance is the ending: do not talk Overseer Barstow into staying if you want the Oversight achievement.

Children of Atom is the Far Harbor line, and it is the only DLC content here with a faction attached. What Atom Requires, The Ablutions, Witch Hunt, The Trial of Brother Devin and The Heretic put you inside a group in open conflict with Far Harbor itself, which is why the Far Harbor endings depend on it.

Side quests worth doing for what they leave behind

Four of our quest pages are collections rather than single quests, and they are the best return on time in the game because they close nothing and several of them hand over a permanent item or companion.

Diamond City Blues is the unusual one. Most quests stop paying out the moment the marker clears, but this one leaves the Latimer and Darcy situations open afterwards, so the quest keeps generating opportunities after it has technically ended. Our guide covers both.

Where the quests point next

Three of the four faction lines end with a weapon or a rank you cannot get any other way, which is covered in the unique weapons guide, and a surprising amount of the unique armor is a quest reward rather than a find. Before you commit to any of them, the builds guide is worth a look, because the Charisma checks in From Within and Duty or Dishonor are the difference between a short quest and a long one.