Fallout Shelter, for the iOS and (soon) Android platforms, is like the Sims in that it allows you to manage a whole vault full of dwellers, and part of that, of course, includes when your dwellers get together and have babies. Dwellers breeding is a great way to increase the population, as well as to select for the statistics that you want to improve in your vault in general, but it takes a bit of care to make sure that you get the highest-stat kids that you can. Read on for a guide on breeding your dwellers in Fallout Shelter!
Almost all of your dwellers will eventually have kids if you stick males and females into the same living quarters with each other, but if you want to maximize the baby-making abilities, select dwellers who have a high charisma rating. They will have babies far more frequently.
If you want to select for a particular set of SPECIAL stats, make sure that you have parents who are strong in the stat that you want to select for. Mixing two parents with high charisma will just cause them to have high charisma children, so diversify a bit. If you want a kid with high strength and agility, you’ll have a chance at it by picking a parent with high agility and a parent with high strength.
Pregnant chicks will never, ever die and will usually have very high happiness. If you want to keep a pregnant chick around forever, put males and females together while the vault is full and the women will literally stay pregnant forever. Once you build a new living quarters, they will instantly give birth and you will have new babies to name.
After awhile dwellers will stop showing up out of the blue, so population will be increased simply by having children, at least until you build a radio station or 2 or 5. If you want to speed along a pregnancy, set the time ahead on the phone or tablet by a couple hours after she gets pregnant. Then speed it along by another three hours after you name the kid, in order to grow the kid into a fully grown adult.
If you want to keep the vault improving, then start booting parents out after kids grow up. The stats will gradually improve by the generation, so send parents to the wasteland or let them die while fighting fires, Radroaches or Raiders and then make their kids have kids. You’ll have to do some tracking to see who’s the kid of who, and who’s the grandkid of who, etc etc.