There will eventually come a point while playing Fallout Shelter that you'll be out of Caps and you'll desperately need some to increase your food supply or solve a variety of other problems. You'll also want to ensure you have people with a large amount of Luck, which will come in handy down the road. Before you pair up the characters, however, look for people who have enough charisma to actually attract someone. It's at this time - and only at this time - that you should pair up your characters and let them do what they will in bed. You might also know that Fallout Shelter allows up to 200 characters in a single shelter. Chances are, you will notice that a few people from outside your shelter are coming in to join your community. OK, so now you've set up your shelter, things are going well, you have plenty of resources, and you feel confident.

So, until you have your place ready to go and you feel you need another mouth to feed and shelter, don't rush two of your Dwellers into bed. And it takes several hours for the baby to become a contributor to your community.

But don't forget that when you bring a baby into this world, you need to feed him or her. Yes, it's an interesting concept that Fallout Shelter lets you pair up two Dwellers and watch as they conceive a child.

Fallout shelter ideal layout