Essentially I want people's thoughts on layout strategy.

It struck me that room upgrade prices seemed cheaper (on a per dweller slot basis) when upgrading a combined 2 or 3 room room. Said differently, there's bulk discount pricing. For instance it might cost 250 to upgrade a single water production room but if it's two combined it might cost 375 (a savings of 125 caps). That encourages larger rooms.

But there's risk with that. If you moved people around then a combined room of 3 diners may only have 2 of the 6 (3 rooms x 2 dwellers each) possibles dwellers. If the room gets attacked it will still get attacked by 3x the normal roach amount. End result is vulnerability that can lead to death or at least high health loss when're rooms aren't fully staffed.


What strategies are people using to best maximize production, minimize cost, and minimize attack risk??? More rooms that are small rooms or fewer but larger?

What room is best to put near the vault door to protect from raiders? The strong people (power plant people). Or endurance types... Are they tougher?

  • 3
    The best thing to do, regardless of the room the raiders go in first, is that room needs to be a 3 room-merged one, filled up (6 dwellers) and them having the best weapons you have (minus the one used in the wastelands). Commented Aug 14, 2015 at 19:03

8 Answers 8


Ok, I will address the issues as I come across them:

  • It is indeed cheaper to build one large room and upgrade it all at once than individual parts (upgrade discount is 25 % for size 2 rooms, 33% for size 3 rooms). If you have the option to build in this manner then always do so.. Running low on some resources though can make getting a single room more important.
    • NOTE: The exception to this, from my knowledge right now, are the radio rooms. A larger room will reduce the time a bit but not increase the chance at the end of that time of getting a new dweller. It is better to have single individual rooms for this (though I will admit I have not answered the door in over a month myself). Radio Room bonus happiness is based only on the number of dwellers assigned to it (observation with a size 3 Radio Room, putting 6 dwellers with 1 charisma or 6 dwellers with 10+ charisma yeld the same 6% happiness boost).
  • Room production is very simple and straight forward. Each room produces a resource of a certain amount. That amount is directly tied to the size and upgrade level of the room. The time it takes for the resource to be made ready for collection is also an initial fixed time based on the same factors. Your workers then combine their appropriate stat together and reduce the time it takes for the resource to be produced. Dweller stats have diminishing returns on production cycle duration (having a dweller with 6 PER in a water room won't give half cycle duration as assigning a 3 Per dweller).
    • Basically this means that one worker with a stat of six is equal to six workers with a stat of 1.
    • Luck adds towards this score for any room and also assists with the random caps bonus you can get. I am not sure what the chance is to get caps but by going over the cap of the primary stat with luck, you can reduce the time and rush failure rate significantly. I so far have gotten one rush to 0% followed by a 6% chance of failure. I have heard reports that you can get 0% twice in a row with enough points. Having all your dwellers with 10 Luck and 10 in the romm-related skill yeld 0 % failure on first rush, increasing with each rush.
  • For the raiders, the room does not matter. Health is determined by the people's levels. Their damage is determined by the weapons you give them. You basically want the first room with someone in it to have the best weapons inside your vault. Endurance -may- have some impact on damage taken but not enough to make it noticeable as compared to level variance of the dwellers (endurance is directly tied to HP gained when they level up : a dweller with END5 will gain less HP when leveling than an END6 dweller, confirmed by reading values in save file [all dwellers have 105 base HP at lvl 1]).
    • My first room was my diner and now garden.. My staff are just armed to the teeth with the best weapons.. 2 of the 3 raiders drop dead before they even make it to the middle of the room.
    • Do NOT use the gate room for defense. You can only put two people in there.. its just not as effective as a full sized room can be.
  • Layout of the vault has nothing to do with the attacks. The only thing to be concerned here is if something happens in an empty room, usually rad roaches but some times fire, that they will spread until a room with people in them are found. After that they will only spread if they kill all of the people in them.
    • Simple rule of thumb, arm everyone in your vault with guns. The best ones should be in your diner to stop raiders since they steal resources vs the other events just annoy the room they occur in. But cycle the weapons from First Room to Wanderers to Everyone else until everyone is armed. As you get better weapons, spread them around and upgrade people.

And so much for a short answer.. If anything needs more detail let me know in the comments.

Edit: Redid the Luck section based on @SkyHiRider's information in the comments.

  • 4
    Good point.. Do not get your 'guards' pregnant.
    – James
    Commented Aug 14, 2015 at 19:43
  • 1
    @JonathanDrapeau There might be a combination going on, Ill look into that.. But I have a power station where everyone has 10 strength and varrying luck and I have like a 9% base level of failure. I then have another factory with everyone having 10 strength and 10 luck and it starts at 0. Luck is definitely a factor, and the majority of the factor from my playing. Ill do some testing and swap out people tonight to see if primary stat affects it.
    – James
    Commented Aug 14, 2015 at 21:22
  • 1
    @James 1 luck = 1 pimary stat = -2% rush fail chance You will have 0% fail for the first two rushes if you have 10/10/+7 on stats
    – SkyHiRider
    Commented Aug 24, 2015 at 17:22
  • 1
    James, you said in your answer that the gate room can fit 4 (and that got my hopes up ;), but it's actually only 2, right?
    – Ricardo
    Commented Aug 29, 2015 at 23:30
  • 1
    As @Ricardo says, it is 2, not 4. Confirmed with my own experiences, gamepedia, IGN wikia and as many other fallout shelter guides as I could find. It is infact a common strategy to have a second room as the "first combat point", due to the fact that you can not have more then 2 dwellers in the vault.
    – user106385
    Commented Aug 30, 2015 at 1:48

First thing you have to know that might not be apparent when you start is that you have plenty of space in your vault for all the needed rooms without having to bunch them up, so for production rooms only build them where you can expand them to have 3 size.

I would suggest creating your rooms around a center elevator shaft so you can expand to three in size on both sides.

When you need to build new rooms you should move on to next level even if you have room for a two size room (will get back to what this space is used for). This will cost more in terms of building elevator and clearing rocks, but in the long run you will save caps due to efficiency of rooms and not having to move rooms.

Production layout

For nearly all purposes it is more efficient to build 3 rooms together. For example the first Living Quarter gives room for 8 dwellers where the next two expanded on it will give 10 each.

The exception to this is storage. Storage is based purely on the number of rooms you have build. This is where you want to use the last two spaces you have left on each level. By only building on every other level you prevent incidents from spreading except to the one room that is to the left of it.

I see other people warning that big rooms are dangerous, personally I don't see a problem with it, if you do not have enough people to fill out the room just don't go directly to a 3 room size.

Build your rooms that do not produce anything (Living Quarters and Storage Room) away from the rest of your rooms and in a shifted fashion like so:

shifted rooms

This will mean if there is an incident in one of the rooms it will not spread and stop by it self fast without having to send anyone to the room.

It will make them the first rooms affected by power outage without the big problems.

Also it makes the rest of your base more manageable.

  • Only problem I see is when you get to 150-200 dwellers, are you forced to build in-between those living quarters because there's no where else left to build?
    – Dave
    Commented Aug 27, 2015 at 15:43
  • @DaveG I am at 146 dwellers and it dose not look like space is a problem. I currently only have two rooms of 3 size pr floor, so 12 people on each floor. There is still 7 rows of empty space between my lowest production floor and the Storage Room you see. That means i have room for another 72 workers no problem without having to build on top of my Storage Room.
    – Blem
    Commented Aug 27, 2015 at 16:42
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    Thanks for the input @RossRidge, while I understand why you would think it would be a good idea it would hurt more than it would help, I will update the answer to why when I am not on a mobile.
    – Blem
    Commented Aug 28, 2015 at 16:59
  • 1
    @RossRidge The very point of the Checkerboard Pattern is that incidents simply die out on their own. Fire, roaches or molerats? - evacuating a room makes it die out faster than actually fighting it. Adding rooms in between would make the disaster spread across entire vault.
    – Agent_L
    Commented Sep 1, 2015 at 14:09
  • 1
    @RossRidge well, if they are left unupgraded and with 1 mid-high lvl dweller then perhaps he/she alone could keep the incidents in check.
    – Agent_L
    Commented Sep 1, 2015 at 16:12

Room Spacing

Someone in this thread mentioned spacing rooms to save money on elevators. That's good but I have since realized it has a much greater benefit: preventing fires / roaches / moles from spreading. If a room borders nothing but an elevator, disasters don't spread!! Which means you can rush endlessly and simply evacuate a room and wait for the problem to go away, instead of wasting dweller health dealing with the disaster. The exception is that training rooms that border each other aren't as risky because you can't rush a training room, so they have disasters far less often. So if you're going to stack rooms, stack training rooms and space utilities.

High Health Rooms First

At some point in the game Deathclaws will start to attack regularly. They kill low level (level, not SPECIAL) dwellers quickly because low level = low health. So think about which rooms you have that often have the highest level dwellers in them. Maybe the utility rooms? For me, it's utilities and also the luck room (lounge) because I like to make sure my highest level explorers have maximum luck. Whatever rooms are usually full of high level players, put them near the vault near. You usually train new dwellers in strength, agility, and perception right? So the gym, agility room, and weapons room are usually full of low level dwellers. Think about that when laying things out.

First Room After Vault Door Should be Water Plant

I think this makes sense because higher perception increases aim accuracy. So if you have a 3-wide water plant with six people, and they all have great guns and good aim, that's a great way to greet raiders.

Put a Big Room Near the Vault Door

Doing this allows the first room raiders enter to have six people. I arm these six people to the teeth and it's worked out well so far. The opposite would be to have the first room be a small room with two people, in which case you'll be outnumbered and will take more damage than necessary.

Food/Water Next to Power Plants

Rooms like living quarters, med bays, and training facilities should never touch a power plant. Such rooms do not belong next to, underneath, or on top of a power room. Try to have the closest rooms be food production and water production rooms. If the power goes out, the closest rooms (production rooms) stay lit and the non-essentials go dark.

Big Rooms Are Risky

You can combine three smaller rooms of the same type, to make one big room. The incentive is to save caps, because upgrades are cheaper this way.

The problem is, if you have only 2-3 people in a 6 person room, you hit "rush", and it fails... you may be in trouble. The failure accident will be proportional to the room size and your room is far from fully staffed. A handful of rad roaches or mole things can kill an understaffed room pretty quick if you don't get them help.

Plan for the Worst

When you fall behind in power the rooms further from the power plants loose power first. When the furthest rooms are water and food rooms and they go dark, things get ugly quick. Avoid it.

When you use smaller power plants, you have better damage control because you can rush the rooms closest to essential utilities.

Also, early in the game having only one big food/power/water room is risky because that's only one or two chances to rush. If you have 3-6 small rooms, you can fail a couple times and still keep trying.


I've got a great tip that everyone is gonna hate for reasons that will quickly become apparent: Building elevators becomes much cheaper if you utilize the "Starting a New Elevator gives you one FREE lower-level elevator" trick.

Basically, Build your rooms out three-lengths wide, and then from the free end of your bottom-most 3-wide room, start a new elevator shaft, making sure there are no rocks immediately below it. The second elevator level down will be built for you, for FREE. Build the elevator the third level down, and start a new room going back the other way. You need the third level down so that this room's opposite-side elevator doesn't join the shaft above it, giving you a new FREE elevator on the other side too!

The elevator shaft trick, in practice

the middle elevator in each of these shafts was given *FREE*

After your facility is fully built, go back and fill all the gaps in your elevator shafts. Employing this trick, you save approximately 25% on elevators in your two-elevator facility, as every fourth level was given to you FREE. It may take a little extra time for your dwellers to get around while you're still building, but the money saved justifies the inconvenience, in the end.

  • 2
    But given that elevators only cost 200-300 caps, you only saved 600 or less and isn't this going to be endlessly painful when you're moving your dwellers around for the duration of your playing this game?
    – Dave
    Commented Aug 20, 2015 at 17:59
  • Elevators cost progressively more, the more you add. Once your facility gets 10 or more levels deep, you're really gonna start feeling the cost of those elevators, especially if you have two shafts. Eventually you'll go in and add elevators where the gaps are anyway, (perhaps when you've reached the bottom level, or decided to quit expanding, or decided the inconvenience isn't worth it, or found a pathfinding bug?). But overall, you'll have saved 25% of the cost by free elevators. And you shouldn't be moving dwellers around much anyway. Why are you moving dwellers around so much? Stop that. ;)
    – Ayelis
    Commented Aug 20, 2015 at 18:08
  • Though it does occur to me, as long as you get the free elevator on both sides, you can fill previous gaps for the convenience. If you do, it will cost more earlier on instead of later on, but it will add up to the same price in the end. Though my dwellers really haven't had much problem navigating back and forth. But you definitely don't really need that top-right elevator square. You'll save ~25 caps per elevator built by leaving that one till the end.
    – Ayelis
    Commented Aug 20, 2015 at 18:13
  • Ha! I don't know more about the energy savings. But I do know that you get the first two free, and every additional free elevator is that many more caps in my jumpsuit pocket. :P
    – Ayelis
    Commented Aug 20, 2015 at 18:24
  • Also, it makes sense to fill in the gaps immediately after getting the free elevator bonus below; it means that in the long run, you won't have to pay the highest cost for them, and you'll get more free high-cost elevator tiles.
    – Ayelis
    Commented Oct 15, 2015 at 18:29

I would say that a merged room of 2 or even 3 is better than many individual rooms because, it seems to me that it may produce more.

To me it does not matter if there are more rad-roaches in the room because if your people are already well equipped it would be pretty easy to eliminate them anyways.

Even though one time the raiders came with laser pistols I was able to eliminate them in the first room (vault entrance) because the people in the entrance have maxed SPECIAL, have high damaging weapons (fat man 22-23 and Enhanced gauss rifle 16-18) and the people also are level 50s also the next room is a diner with a room of six people leveled 25-41 and they all have enhanced flamers (15-17) and have some maxed SPECIAL.

  • I think it's a preference. Most people just build big rooms, true, but every game makes you encounter problems that introduce the possibility of failing/dying/losing. In the vault, the threat is from raiders, fires, rad roaches, weird burrowing mole things, and more to come as I progress? Smaller rooms carry less risk. Smaller rooms means if a problem/shortage comes up and I have to shift dwellers around, I'm less vulnerable. Issues in 1-wide rooms spread 3x slower than in a 3-wide. It's easier to keep every 1-wide room fully staffed too, meaning less chance of death from failures.
    – Dave
    Commented Aug 20, 2015 at 17:58

Regarding the room layout in general, I have found a single rule that really helps:

Build all your rooms in a staggered pattern.

It costs a bit more in elevators, but it means that no incident will ever spread. That means that you can simply empty out any room as soon as an incident occurs there. In particular, the fire incident actually stops a lot faster if the room is empty, compared to if the room has dwellers in it (even if it is full of high-level dwellers!)

If you are going for "Survival Mode", the staggered layout is almost mandatory!


You really want most or all of your dwellers to be productive at all times, so you should want your first top-level room to be a resource production room. Early on there aren't any resource production rooms that focus on endurance, so I'd put a Water Room on the top level for the Perception bonus, which is said to improve aim for ranged weapons. Strength would be useful if you had melee weapons, and Agility would be nice if you were worried about getting hit, but you mostly want high DPS, so Perception is really your best bet in this situation. Also make sure there is at least one of each gender in the room, as this supposedly deters unhappiness, but avoid getting them pregnant, for reasons listed by others.

As others have also said, Staffing the vault door is basically worthless, but I also consider upgrading the vault door to be worthless (outside of objectives), since now you already have armed dwellers waiting on the top level. Save your caps and your time!

  • 1
    I skipped upgrading my door as well. Do you know if upgrading it gives a chance of keeping them out completely or just gives you more time before they break through? Early in the game I upgraded it and the raiders came minutes later and still broke in.
    – Dave
    Commented Aug 20, 2015 at 18:06
  • I've never had a door repel raiders. Even a fully upgraded one. They always break through. It's just a matter of how long it takes. :/
    – Ayelis
    Commented Aug 20, 2015 at 18:28
  • 1
    Yeah, so agree it is pointless. Now if I could only play )-: iPad Mini... my vault outgrew my memory limit. Damn Apple and there history of being stingy on memory/HD space!! 16GB baseline in 2015!?!?!
    – Dave
    Commented Aug 20, 2015 at 18:34
  • I upgraded the vault door for one of the objectives - it was that or build rooms I didn't need at the time.
    – Freso
    Commented Nov 20, 2015 at 10:33
  • I guess they've added objectives to upgrade the door (or rooms in general) since I wrote this. In that case, I rescind my comment about upgrading the vault door being worthless. ;)
    – Ayelis
    Commented Nov 20, 2015 at 17:47

I've recently come across a new layout strategy that doesn't really complement either of my previous answers, but it's too good not to list here, so I'll add it here. Call it the Molerat Defense. To start with, you're going to have to destroy some of the preliminary rooms.

Set it up like this:

The Molerat Defense in action

If you want to utilize your vault's space effectively, build your top floor all the way to the edge, and add an elevator at the end. The individual rooms you choose for this level may vary. (Though in one of my other answers, I suggest putting a Water Room on the top level to ensure your front-line dwellers have better Perception for ranged attacks. I've also seen the suggestion that 2-wide rooms should be reserved for storage, stimpak or radaway production.)

If you want to fill your vault's available space entirely, destroy the second-floor rooms that you've built during the tutorial and rebuild that floor when you can. The sooner, the cheaper. And don't forget to use the trick in my other answer to save 25% caps on those expensive vertical elevator shafts!

The important part of this setup is the positioning of the Elevators. Elevators should surround your entire vault. Leave no dirt untouched. And that includes the dirt at the bottom of your vault.

The Bottom of the Molerat Defense

Yes, be sure to line the bottom-most row of your vault with an entire row filled with 26-odd elevators. (Dirt at the top of the vault doesn't seem to count as of this writing, but if you're made of caps, you could fill it with elevators just to be safe!)

As others have stated, this strategy may not be beneficial in a fire or radroach attack. But utilizing this method you can COMPLETELY eliminate molerats as they only attack rooms bordering dirt unprotected by elevators. Molerats can be absolutely devastating in later stages of the game as they will quickly sap your power supply, which can bring down your entire production flow.

(Thanks to QuantumCurt and Aslum for these images!)

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