|The following is based on Fallout Shelter and some details might contradict canon.|
The game's four themes are based on the four different factions featured in Fallout 4: the Minutemen, The Railroad, the Brotherhood of Steel and The Institute. Once themes have been applied to rooms, one can change the themes off and on at any time but when they do the vault must reload.
Once you have collected all theme fragments, whenever you get one you just get caps like weapon/armor recipes.
Obtaining theme fragmentsEdit
There are two basic ways of obtaining theme fragments:
Theme fragments are treated as a higher priority on the Quest Rewards screen than rare items, although they are fairly common find.
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