

As an effect of upgrading, the capacity of the room and its production increases. To find upgrading menu, select the room, and then click on the arrow that will appear instead of a hammer (upper right corner).
#FALLOUT SHELTER 3 ROOM UNDERVAULT DOOR UPGRADE#
There are two upgrade options and its cost depends on the room's category as well as on size - upgrading two rooms of the same kind but of different sizes has different cost. Not only can you merge your rooms but you can upgrade them as well. Keep in mind that the higher the level you try to work out, the more time it takes, so train only these skills that are useful in the dweller's job. When you send your dweller there, he or she can work out their skills for some time and then it gets improved permanently by one point up.

Special stat training rooms - when you reach 24 dwellers you get access to your first training room in which your dwellers can work out their skills. Dwellers with well-developed intelligence are welcome to work in one of them. This category also contains rooms in which you can produce Stimpaks and AntiRadars. Remember to assign right dweller to the right room as each of them desires different S.P.E.C.I.A.L skills (strength is useful when producing energy, perception when gaining water and agility in the restaurant). Resource production and storage rooms - available from the beginning. Expansion of it proceeds mostly in a down direction so remember to provide enough of elevators (two for each level sounds good) to make it possible to move between levels efficiently. Elevator let you get to the lower level of your Vault. Vault Door can be improved like any other room - it impacts positively on frequency of raiders' attacks, on better strength and also provides more time to organize defense. Access rooms (access to wasteland and lower levels): Vault Door and Elevator. Each floor is balanced with residence and production rooms so dwellers can quickly be dispatched to empty rooms in case of incidents.Subsequent rooms get unlocked when you reach a certain level of population. Other than that, fairly self explanatory? Start with single rooms and expand as needed. Also, later in the game when you get a ridiculous objective like "put out 100 vault fires" - you can rush the kill room into oblivion and incidents are stopped almost immediately, because the incidents are so weak and your dwellers are so strong. Merge, but don't upgrade until your dwellers are higher level and better equipped. In fact, I prefer not to upgrade at all when I'm starting out. Never upgrade the kill room, since you don't want your dwellers to be weakened in the event of a raider attack. If you upgrade rooms, radroach attacks and fires get stronger. Put your highest level dwellers and your best weapons in this room to fight raiders. I call this the kill room, since it's always the first room raiders will hit. This allows you to put your first production room immediately to the right of the vault door. Step 1, kill room: Build a residence directly under the vault door and destroy the starting residence.
