Vault 111 - 3 vaults combined into one. Every inhabitant is cloned from birth. 2 of the vaults are populated and mixed with both real people and clones ages 1 - 20. No one in either vault knows if they are a clone or a real person. All they know is that they have a 'twin' exisiting in the other vault who could be a clone of them or vice versa. The overseer is the only one with this information.

Both versions of you gets to live a 'normal' childhood. Throughout their childhood, the inhabitants and their clones are sent annual progress reports on their birthdays of each other's lives and how they stack up and compare against their 'twin'. At the age of 21, the inhabitants get to meet each their clones and talk for an hour alone.

The inhabitants and clones must then explain their life victories, lessons and defeats in front of a voting commitee consisting of humans, clones and the overseer. The inhabitants and clonea get to bring 3 friends with them to plea their life and worth to the commitee on which is the better version of them and would be most beneficial to society.

The one voted 'most productive, beneficial and worthwhile' would be allowed to live. After the life trial is over, the overseer would personally reveal to them if they are a clone or a real person. They would then be given a chance to leave the vault, only if they are willing to kill their 'twin'. If they refuse to kill their 'twin' they live out the rest of their lives in captivity, in the 3rd vault after watching their 'twin' get gunned down in front of them.