Generally you’ll follow the same few steps:
Pair up two dwellers Put them into living quarters to socialize Eventually the female dweller will become pregnant and deliver her baby, which eventually becomes an adult dweller
This is a simplistic breakdown, but we can look into the process in more depth too.
Step One: Pairing Dwellers
When choosing dwellers that you want to pair together, you can go about it two different ways. The first way you could pair up your dwellers is by just throwing two different dwellers together. As long as it’s a male and a female, they’ll get it done, right? The second way you could pair dwellers is by actually looking at what stats you need. Say you require a dweller with a high Agility stat. You would then look through your vault for two dwellers who have high agility. One male, one female. You want to make sure at least one of these dwellers has a high charisma stat though. Having a high charisma stat will make sure they socialize quickly. The quicker these two dwellers socialize, the quicker the female will become pregnant, and thus the quicker you’ll have a new baby dweller.
Step Two: The Living Quarters
Once you’ve chosen the two dwellers that you’ll be pairing together, you’ll want to put them in the Living Quarters. You can do multiple pairings at once if you have a larger Living Quarter built. However, if you want to make sure the specific pairing you picked out happens, they should be the only two dwellers in the living quarters. This is because if you have more than one pairing, they’ll shift around until the dwellers find the person they want to socialize with. And once your dwellers are paired in the living quarters, they’ll begin to socialize. After they begin to like each other, they’ll then go to the back and the female dweller will come out pregnant.
Step Three: Pregnancy
When your dweller(s) come out pregnant, you’ll still be able to assign them to a room. They’ll also still work, but will be of no help during emergencies like fires or attacks. For this reason, most players just leave pregnant dwellers in the Living Quarters. At this point you’re also able to reassign the male dwellers that you used, unless you wish to pair them with another female dweller. Pregnancy takes 3 hours in total. At the end of those 3 hours, a baby dweller will be born. This baby will then mature into adulthood after another 3 hours in the vault.
