The game is a simulation of managing a refuge. As an Overseer, you have to control the essential aspects of life in the Vault, especially: energy, food, water and the number of inhabitants. Your task is to develop and expand your shelter, as well as to fight enemies, to resist the attacks of raiders and other representatives of the Wasteland.

To obtain resources, you need to assign people to the appropriate premises, properly distributing their skills between strength, perception, endurance, charisma, intelligence, agility and luck. Each character characteristic will affect how well he produces a particular type of resources and how high his chances to survive in the Wasteland.

An essential aspect of the game is the correct use of resources and their balance. And with a deficit of one, there are difficulties. For example, the lack of electricity disrupts the premises, the lack of water leads to radiation exposure of residents, and food — to the loss of health. You also need to protect themselves from attacks by raiders, mutated rats, ghouls and other creatures.