Fallout Shelter rooms

There are a total of 20 available room types that begin at level 1 and can be upgraded with caps to a maximum of level 3. Rooms can also be merged up to two times by placing an identical room of the same tier next to it. Generally each room can facilitate two dwellers. Merged rooms accumulate up to 6 dwellers. Production rooms require a specific S.P.E.C.I.A.L trait to run, while training rooms increase a specific trait of the selected dwellers. Production rooms can also rush production.

Room overview
The cost of each new room is dependent on the number of those rooms already in your vault. E.g. Your first Med Bay is 500 caps, while your second Med Bay costs 600 caps, and so on.

Production Rooms
Production rooms yield one resource, except for the Nuka-Cola bottler which produces food and water. Production time is dependent on the assigned dwellers' total trait level for the room's required trait. E.g. four dwellers with Strength 5 in a double-generator room are as productive as 2 dwellers with Strength 10 in the same room. Production times are also modified by the room's size, level, and the working dweller's happiness. Although it is not visible in their SPECIAL stat bars, wearing outfits that raises traits beyond 10 increases production nevertheless. Once a room has produced a load, they do not produce any more until you collect the resource. Depending on the luck of the workers, collecting the resource may also give a sum of caps.

Rush Production
Production rooms can "rush" to produce resources quickly. Depending on the probability given in-game, the room can instantly yield resources, experience and a number of caps equal to the percentage of the chance taken. A failure on the action leads to an inevitable incident in that room, either fire or radroaches. Each try to rush production, whether successful or not, raises the chances to fail the next rush until the chances to fail surpass a 75% mark. The room's rush penalty slowly decays over time. The total chances to fail a rush in a specific room is affected by the luck and the traits of the workers and the room's current rush penalty. With a successful rush attempt all workers of a room gain a total of 10 points happiness over the next 30 seconds. A failed rush attempt lowers the workers happiness depending on the incident.

Training Rooms
These types of rooms raise one of the traits for the dwellers stationed in it. Training time depends on the dwellers' current level and happiness, the room level and how many occupants are in the room. Going from level 1 to level 2 takes a few minutes while going from 9 to 10 takes up to 20 hours. Dwellers train faster with more dwellers in the room.

Merged Rooms
A maximum of three rooms of the same type can be merged to one bigger room. Rooms are automatically merged by placing a room of the same type next to an existing room of tier 1. If placed next to a room of higher level, the new room will be merged as soon as it was upgraded to the level of the existing room. All beneficial effects of the two rooms are cumulated upon merge: A double training room will train up to four dwellers, a triple training room up to six. Merged rooms have advantages compared to the same number of unmerged rooms. Upgrading merged rooms costs less than the cumulative upgrade costs of the same number of unmerged rooms. So consider merging rooms to triples before upgrading them. Also merged rooms are more productive and effective: Production rooms will generate resources faster while training rooms can hold more dwellers which reduces training times.

Room Layout
In the current design of Fallout Shelter the first floor of your vault can hold five rooms (whether merged or not does not matter) All following floors can hold eight rooms. In addition all floors can hold up to two elevators. Adding more than two elevators per floor will sacrifice space for other rooms.