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Fallout 4 Vault 81: Uncover All The Secrets Of The Vault

By Game Gear Plus
September 24, 2023

Home » Gaming » Fallout 4 Vault 81: Uncover All The Secrets Of The Vault

Last Updated on September 24, 2023

Fallout 4 is one of the best entries in the Fallout franchise that Bethesda has ever graced us with. The game is packed, and I mean packed, with locations to discover and quests to complete. One of these secret locations that you probably won’t be stumbling to is the Vault 81 in Fallout 4.

So, we’ll be covering this elusive Vault 81 in detail. Our guide includes everything you need to know about the Vault, from its location to the different quests you can get here.

What Is The Vault 81 In Fallout 4?

Vault 81 in Fallout 4 is the only functional Vault in the Commonwealth that withstood the aftermath of the Great War. It has several friendly inhabitants going about their daily lives. This self-sufficient Vault has survived this long due to its reliable connections and trade system with the outsiders.

The one leading the charge is Overseer McNamara, who runs the Vault’s day-to-day operations. You’ll also find a wide range of characters to hold conversations with, including Officer Edwards, whom you first interact with upon reaching the Vault’s entrance.

You’ll be able to secure valuable loot and undertake several quests from NPCs in the Vault. So, let’s take a deep dive into what awaits you when you finally decide to give Vault 81 in Fallout 4 a visit.

How To Enter Vault 81 In Fallout 4

There are essentially two ways that you can enter Vault 81. One is through passing a speech check, which includes establishing yourself as a fellow vault-dweller to Officer Edwards and Overseer McNamara through the comlink at the Vault’s entrance.

The other way is to find fusion cores requested by Overseer McNamara as a ticket to entering the Vault. Here are both of the methods in detail. The choice is yours which path you want to take:

Locating Vault 81 in Fallout 4

Before we talk about how to gain access to the Vault 81, you’ll first have to find where it is in Fallout 4.

You can find Vault 81 in Commonwealth’s Central Area, south of Oberland Station and west of the Chestnut Hillock Reservoice, right next to the train tracks. You can also see its location marked right on the map above.

Once you reach the general area, you’ll see an area with desolated shacks and scrapped vehicles. Just cut through this abandoned area, and you’ll see the cave entrance that leads to the Vault 81’s entrance.

#1 Entering Vault 81 By Passing Hard Charisma Check

This method of gaining entrance into Vault 81 is for players who have put their points into Charisma and have a decent level in it. This way, you can sweet-talk your way into the Vault 81. Simply follow the dialog options I’ve listed below:

Edwards: Hold it right there. Vault 81 Security. I don’t know where you got your hands on a working Pip-Boy, but you better start talking.
Select the “Vault 111” option.
Edwards: And what sort of business are you looking to take care of here in 81?
Select the “Looking To Trade” option.
Overseer McNamara: For newcomers, we like to operate on exchange. You help us, we help you.
Select the “Help A Vault Dweller” option.

And this is the end of the dialog choice you have to make to gain access to Vault 81. After your last dialog choice, Edwards will remind McNamara that the player came from Vault 111 and they’re in possession of a working Pip-Boy.

Upon hearing this, McNamara will allow your entry into Vault 81, and the gates will start opening.

#2 Entering Vault 81 By Acquiring Fusion Cores

Now, for players who don’t have enough Charisma level to sweet talk their way into Vault 81, they’ll have to do a bit of legwork. After your conversation with Overseer McNamara, she’ll instruct you to fetch a few fusion cores as a payment to enter the Vault.

TIP: You can use both used as well as fresh fusion cores as payment for entering Vault 81.

So, you’ll either have a few on hand, and you can just tell her, and she’ll open the Vault door so you can hand them over. Just in case you don’t have any fusion cores, I’ve got you covered. Here is a list of a few places where you can find fusion cores with ease:

ArcJet Systems Building: You’ll find 2 fusion cores here inside the building. One in the generator area behind the rocket control room and the other one in the warehouse north of the building.
Atlantic Offices: You’ll find 1 fusion core on the roof of the building.
Back Alley Bowling: You’ll find 1 fusion core here on the second floor underneath the metal shelf behind the bar.
Boston Airport: You’ll find 1 fusion core here right after the Reunion quest as it spawns in the generator on the terminal ground floor.
Boston Mayoral Shelter: You’ll find 1 core inside the generator in the utility room.
The Castle: You’ll find 3 fusion cores here. One in the armory and the other two inside Sarge Sentry Bot.
Cambridge Polymer Labs: You’ll find one core in the display case in the director’s office on the second floor.
Concord Civic Access: You’ll find one fusion core right behind a pipe on the west side of the water drain of the sewers.
Factory: There’s a factory in the northeast of the South Boston Police station. You’ll find the core on the second floor inside a generator.
Federal Ration Stockpile: You’ll find 2 fusion cores here. The first one you can find is inside the generator behind the bunker, and the other is in the underground bunker.
Fort Hagen Command Result: There’s 1 fusion core inside a generator on the west side of the compound
Greentech Genetics: You’ll find 3 fusion cores here. One can be found on the 8th floor of Zziada Bsa Mi Dza b.

After you acquire the required fusion cores, interact with the commlink, and the Overseer will unlock the door. After you enter Vault 81, you’ll simply have to hand over the fusion cores to the Overseer McNamara. After that, you’ll all be set to explore the Vault and do some fun quests.

Story Behind Vault 81 In Fallout 4 (Lore)

Spoiler Alert: This section of the article contains spoilers for the lore of Vault 81 in Fallout 4. This will spoil any quests or story bits you’ll slowly collect throughout your exploration of the Vault 81.

When you walk across the halls of Vault 81, it all looks jolly and friendly. But it isn’t what meets the eye. In reality, what looks like a normal vault was a setup for unethical health experiments on vault dwellers. Vault-Tec’s original plans were quite morbid before it became this friendly community that you are greeted with.

There are 2 main sections of Vault 81 that are completely separate and sealed away from one other.

The first section is where the vault dwellers will live during the nuclear fallout.

The other hidden section contains medical and research equipment for scientists. This is the section where you’ll get CURIE (Contagions Vulnerability Robotic Infirmary Engineer Bot.)

This section is creepy, as it contains observation decks with one-way mirrors so scientists can monitor the vault dwellers.

The original plan for this Vault was to hire scientists and conduct human experiments on the vault dwellers. The main goal was to develop antibodies to combat different human diseases.

Originally, scientists used molerats as guinea pigs. But they later started experimenting on the vault dwellers themselves.

The main goal behind this idea was to create a society of disease-free humans. However, the unethical experimentation that was needed to achieve this resulted in several lost lives of vault dwellers.

Vault 81 Secrets and Loot In Fallout 4

There are several items of interest that are locked away in Vault 81. We’ll list some of the most useful items that you can get you can acquire.

Mini Nuke


Weight	12 Pounds
Difficulty	Survival Mode
Value	100 Caps
Location	You can find it in a tipped-over locked inside the Broodmother’s room

Mini Nuke was developed at Fort Strong, which was originally part of the Fat Man project in Fallout 4 universe. It’s considered the strongest weapon in Fallout 4 that’s capable of decimating your foes into dust.

The mini nuke has 4 main components:

Detonator Shell: Contains the sub-charge that detonates when it’s ignited with an M42’s striking pin.
Stabilizer Fins: These ensure that the nuke’s trajectory remains stable and it doesn’t tumble mid-air.
Hemisphere Core: It contains the main nuclear core.
Bervillium Contact Fuse: It begins the nuclear reaction leading to the destructive impact.

Vault 81 Tech Password


Use	Opens up secure access terminal located next to the Research Comms Room
Location	You can find it in the research comm room on the second level with cells

There’s a secure access terminal on the second level of Vault 81 that you can hack to avoid the final fight with the Molerat queen. Why you’d want to avoid it? It’s because one hit from Molerats can infect you with the genetically modified disease they’re carrying.

However, if you haven’t got enough points invested into intelligence, then you’ll need the Vault 81 Tech Password. It’s located on the same level inside the room at the end of the walkway. However, you’ll have to fight your way through Molerats.

Stealth Boy


Weight	1 Pound
Value	100 Caps
Effects	Gain Invisibility For 30 seconds
In-Game Description	The Stealth Boy is a portable device that you can activate on command. It generates a modulating refraction field that makes the player temporarily invisible for a period of 30 seconds.
Location	You can grab it off the desk in the medical lab inside the secret vault

Stealth Boy is a great device if you take a quieter approach to your mission as opposed to going all guns blazing. It can render you invisible (for 30s). It makes it easier to sneak past enemies or pick them out individually.

This is a special variant of the Stealth Boy that doesn’t require the player to wear on their wrist. Instead, it can be carried and activated right from the player’s waist.

Medicine Bobblehead


Weight	0 Pounds
Value	300 Caps
Effects	+10 Stimpak Healing
In-Game Description	The smart man knows a bandage only hides his wounds.
Location	On the desk inside Curie’s office

You’ll find the medicinal bobblehead quite handy if you want a nice upgrade to your heels. It’s one of the best miscellaneous items in Fallout 4 that helps you permanently increase your heals from stimpaks by 10%.

Do note that the effects of Medicinal Bobblehead are multiplicative and not additive. If you have no rank in the Medic, your Stimpak healing will go from 30% to 33% health. Similarly, it’ll scale according to your Medic rank, i.e., 40% will become 44%, 60 will become 66%, and so on.

Vault 81 Cure


Weight	0.3 Pounds
Value	400 Caps
Effects	Cures Molerat Disease And Grants +50% Hit Points
Addication	0%
Location	You’ll get it from Curie after you allow her to open the door

Remember that human experimentation I was talking about earlier that Vault-Tec scientists conducted in Vault 81? Well, they used Molerats as test subjects and ended up creating disease-infested Molerats that can spread with just one hit.

To cure and make yourself immune to that disease, Curie created a specialized cure that you can administer. It will remove any diseases that you might have got from fighting all those Molerats and put a halt to the dying plan.

However, if you got lucky and somehow didn’t get the disease from Molerats, you can instead give it to Austin. It’ll not only save his life and give you some positive Karma points but also receive the Syringer Rifle.

Syringer Rifle


Type	Rifle
Damage	Special
Damage Type	Varies
Ammo Type	Syringes
Ammo Cap	1
Fire Rate	3.33 RPS
Range	Stub Barrel: 21.93 meters Short barrel: 32.9 meters Long barrel: 58.49 meters
Weapon Slots	Barrel, Stock, and Sights
Weight	4 Pounds
Value	100 Caps
In-Game Description	The Syringer Rifle is quite a rare weapon that’s custom-made to shoot medical syringes at your enemies. The enemies will suffer the effects of the chemicals inside the syringes.
Location	Received as a reward from Jacob for completing Hole In The Wall quest after giving the Vault 81 cure to Austin

The Syringer Rifle is a rare pneumatic weapon in Fallout 4 that shoots special syringes at your enemies and puts them under status effect.

You can craft 9 types of syringes with their unique status effects to use with the Syringer Rifle. These include both combat and non-combat syringes to help you pick whichever is best for your playstyle. Here are the syringes you can craft to use with the Syringer Rifle:

Berserk Syringe: Put target in a frenzy for 2 mins
Bleed Out Syringe: Apply 30 pts of damage over time for 10 secs
Bloatfly Larva Syringe: Bloatfly spawns from within the target on death
Endangerol Syringe: Reduce target’s damage resistance by 25% for 2 mins
Lock Joint Syringe: Paralyze target for 10 secs
Mind Cloud Syringe: Vanish the player in the target’s vision and reduce its detection ability for 30 secs
Pax Syringe: Makes target non-violent for 30 secs
Radscorpion Venom Syringe: 40 pts of damage over 10 secs
Yellow Belly Syringe: Cause target to flee for 30 secs

All Quests You Can Find In Vault 81

There are a lot of quests you can undertake in Vault 81. You’ll have to talk to the friendly NPCs around the Vault to get these quests. These quests range from easy to difficult, but the rewards will match the difficulty. So here’s a list of all the quests you can do in Vault 81:

Vault 81

This is the introductory quest that will get you into Vault 81. When you reach the vault entrance and connect your Pip-Boy to the terminal, you’ll be greeted by Officer Edwards and Overseer McNamara.

Now, this is where the quest will branch out. If you have enough skill points invested in Charisma, you can easily pass the hard check and enter the vault 81 right then and there.

However, if you don’t have enough points in Charisma, you’ll need to fetch Fusion Cores for Overseer McNamara as a toll for entering Vault 81.

Vault 81 Tour

This quest is basically how you’ll break ice being with the Vault dwellers in 81. You’ll be greeted by Austin Engill, who’ll offer to give you a tour of Vault 81 for 5 caps.

Now, you can also skip paying Austin (you cheapskate) by passing a Charisma check. Doing this will let you take on this quest for free.

Once you’ve started the quest, Austin will give you a guided tour of the Vault 81. You’ll go from room to room, and once it’s over, you’ll receive +75 experience points.

Maintenance Man

You’ll find Calvin hanging around right outside the Overseer’s office. You can start a conversation with him, and it will mark the quest Maintenance Man in your log.

Now, you can come to Kevin and sell him tools for 15 caps a piece. Here’s a list of tools that you can make quick caps off from Kevin in Vault 81:

Ball-Peen Hammers
Screwdrivers
Wrenches
Adjustable Wrenches
Combination Wrenches
Hammers

You cannot sell all kinds of tools to Kevin. He won’t be buying any sort of gardening, cleaning tools, or common hammers from you.

Tip: If Kevin isn’t spawning for you in Vault 81, he might be bugged. In that case, open the console, type Prid 00153855, and press enter. After that, type moveto player and hit enter again. This will get you to Kevin in no time.

Fertilizer Woman

Dr. Penske is the chief biologist of Vault 81 who leads the hydroponics lab in Vault 81. You can interact with her, and she’ll give you a vault-grown Mulfruit strain to keep.

Once you consume the Mulfruit and interact with her again, she’ll ask for bags of fertilizer to help her with farming. So, you can farm for fertilizer in Fallout 4 and sell them to her for 25 caps each. That’s quick money if you ask me.

Short Stories

Another fun little side-quest you can do in Vault 81 is called Short Stories. To trigger this quest, you’ll need to talk to the school teacher, Katy. She’ll ask you to join her class and tell stories about the Commonwealth to children.

If you choose to accept her request, you’ll have to wait until 9 a.m. for the class to be in session. Once it’s the right time, go to the classroom, and you’ll find Katy sitting at the teacher’s desk. Interact with her, and it’ll begin the quest.

Even though Katy will advise you to steer clear of any bloody or gory stuff, anything you tell here won’t affect your karma negatively.

During the dialog, one of the students will ask you if you’ve fought a Deathclaw before. You can either entertain the question with some details or simply ignore it and move on.

Either way, you’ll complete the quest, get Grognak the Barbarian comic book as a reward, and some easy experience points.

Here Kitty Kitty

Here, Kitty Kitty feels like a proper side-quest compared to other ones on this list. You can start this quest right after getting a tour of Vault 81 from Austin. At the end of the Vault 81 Tour quest, Austin will introduce you to Erin.

After speaking with Erin, she’ll inform you that her pet cat Ashes has gone missing, and she’ll request you to find it.

To find where Ashes went, you simply need to exit Vault 81 and head east towards the Chestnut Hillock Reservoir.

Once you cross the river and enter the area shown in the image above, you’ll find Ashes hanging around the pier. Simply interacting with it will send it back to Erin in Vault 81.

You can either escort the cat back to the Vault if you have a sense of safety for the digital feline creatures. Or you can just book it back to Vault 81, talk to Erin, and finish the quest to get your experience points and a fusion core.

Hole in the Wall

Heads up, Hole in the Wall is the longest and might be the toughest side quest you’ll do in Vault 81.

Now, to trigger this quest, you’ll first have to donate your blood to Dr. Forsythe in the infirmary. After you’ve done that, you can either pursue the Here Kitty Kitty quest or simply wait 24 hours before returning to the Vault 81.

Tip: While you wait for the quest to begin, I recommend equipping yourself with a nice high-capacity automatic weapon like Spray N Pray. You should also have fragmentation mines as well as a high amount of health to get through this perfectly.

Once you return to the Vault after 24 hours, you’ll hear that Austin (that nice boy who gave you the tour of Vault 81) was moved to medical bay. This happened because Austin was bitten by a Molerat and fell severely ill.

Once you head over to the infirmary, you’ll see Dr. Penske, Dr. Forsythe, and Bobby De Luca having an argument. You’ll come to know about a secret Vault 81 and how there’s a cure for Austin’s condition there.

Once you interact with Dr. Penske and agree to help Austin, this will start the Hole in the Wall quest.

After the quest starts, you’ll follow Bobby De Luca into the reactor room, where he’ll reveal the entrance to the secret Vault 81.

Now, this is where things will get tricky for you. This area is infested with Molerats, and even one hit from them will infect you with a disease. This is where automatic weapons and mines will come in handy.

Tip: Make sure to dismiss any companions you have with you as they can also contract this disease from Molerats. Also, try to quick-save a lot, as you can always replay a section in case you got bit.

From here on out, the mission is quite linear: follow the stairs up, and you’ll encounter your first Molerate. After killing it, go to the end of the catwalk and take a left into a room.

There’s a terminal here giving you a bit of backstory about the Vault. Once you’re done reading, open the sliding door to enter a hallway with two ceiling turrets.

Take care of the turrets with explosives or flamethrowers. Then, hack the terminal on the wall to get the Protectron to help you out.

Fight your way to the upper levels of the secret Vault 81 until you see a secure access terminal. This terminal will open up the door that will lead you to the cure, but it’s locked. Here, you can either hack the terminal and access the room, which will save you a lot of effort.

Alternatively, you can move ahead and lay down the mines and prepare to fight the Mole Rat Brood Mother.

After you take it down, head to the room at the end and grab the Vault 81 Tech Password. You can also get a Mini Nuke, stimpaks, and a Stealth Boy.

Now, you can head back, unlock the door with the secure access terminal, and enter the room.

Here, you’ll meet Curie, a nanny robot who’ll tell you that she’s finished making a cure for every disease known to mankind 80 years ago.

Simply tell Curie that you’re with Vault-Tec, and she’ll gladly hand over the cure to you. After this interaction, you’ll head to the elevator and get back to the main Vault 81.

Heading back into the infirmary, you’ll hand over the cure to Dr. Forsythe so he can administer it to Austin. And that’s it, you’ve cured the little boy and got a Syringer Rifle as well as your own room inside Vault 81.

You’ll also add Curie to your list of companions that you can take with you through the wastelands.

Dependency

The final quest for Vault 81 in our list is dependency. You’ll go and meet Tina De Luca in the reactor room, where she’ll tell you about Bobby De Luca’s drug addiction.

His addiction has reached life-threatening stages, so he needs to be convinced to quit.

So you need to head over to Bobby’s room right in front of the electrical plant’s entrance. Once inside, you need to talk things through with Bobby.

You must have high Charisma in order to pass the speech check and convince Bobby to quit using drugs. Once you’re done convincing him, head back to Tina and get your experience points.

Tip: If you have high enough Charisma, you can even convince Tina to move into a settlement with you.

Did You Find Out All the Secrets Of Vault 81 In Fallout 4?

And there you have it, folks. I’ve listed everything you need to know about the Vault 81 in Fallout 4. I hope you have just an amazing time exploring this Vault, uncovering its mysteries, and completing quests as much as I had writing this guide.

If you think I’ve missed something or there are questions popping up in your mind, don’t hesitate to shoot a question down in the comments below. But for now, Vault dwellers, I’m out!

Fallout 4 Vault 81 – FAQs

Where is the secret part of Vault 81?

You can enter the secret part of Vault 81 through the reactor room. However, the secret entrance is only accessible during the Hole in the Wall quest.