The people in your fort are called survivors. There are survivors to carry out various missions, designed to acquire resources for your fort and make the outside safer, increasing your chances of continuing to exist. Survivors not assigned to a specific mission remain within the fort in the Guard Service, keeping other survivors safe from looting zombies.
Unless they have a camper perk, each survivor needs a home to live in and, unless changed by privileges or politics, will consume 1 unit of food per day. Every survivor is classified into five different abilities, has a happiness level from 0 to 100, can equip a weapon and a non-weapon, and can have several advantages and disadvantages.
New survivors can be acquired through recruitment missions, sometimes appearing through random events whose occurrence can be increased or decreased based on research and policy, and by destroying factions you have the option of recruiting 2 unfortunate survivors.
Some survivors may have a child with them, which works as a disadvantage for the characters who "equip" them. Children act as an item that is not a weapon that reduces all statistics but increases happiness. Children consume half a unit of food every day. Unless the fort's "Children must go to school" policy is in effect, each child must be equipped with a survivor or the game will automatically assign a survivor to equip the child. Each child has an instant hint that shows their age, and 13-year-olds have a chance to "grow up" at 14 and be converted from an item that is not a weapon to a full-fledged survivor who needs housing and can be sent on missions.