Fallout Shelter is a time management simulation game. Set in the Fallout wasteland after a nuclear war, you play as an Overseer of an underground bunker. You accrue currency to build rooms, attract people and train them to provide resources, craft weapons and go on dangerous missions. It's an unusual combination of simple endless strategy set in a wider universe drawn from the other Fallout games.

Gameplay involves selecting rooms and persons to upgrade, repair or build. You can select individuals to move around the vault, assign them jobs, train them up, or send them on missions. You can name your inhabitants and even encourage relationships that provide babies that grow up quickly to be useful workers. You need money that is gained by levelling up your dwellers, exploring the Wasteland, going on missions, completing achievements, as well as finding the mysterious stranger that randomly appears and disappears in your vault.

Missions provide your vault with weaponry, outfits, pets (which improve statistics of their owner), junk to build weapons and outfits in the vault, and currency when they return. They are often multi-part and follow a simple storyline. The game uses real-world time to get to missions, although you can accelerate this with purchasable cola bottles or take a risk on a negative outcome by "rushing" the room.

Combat is automatic. Creatures and other enemies randomly enter the vault and will attack your people. If they are armed they will fight them off. Pregnant dwellers and children will run away. Dead dwellers can be revived if you have enough money. Dwellers out on missions automatically attack what is in the room and you monitor their health and give them syringes and radiation medication as needed to prevent them dying. If you lose all your people out on a mission, then it will fail.

The Fallout Series started in 1997 as a PC turn-based adventure game and has developed into a vast multi-console open world experience. Other games in the series include:

• Fallout 1997 (Mac, PC)
• Fallout 2 1998 (Mac, PC)
• Fallout 3 2008 (Windows, Xbox 360, PS3)
• Fallout: New Vegas 2010 (PC, Xbox 360, PS3)
• Fallout 4 2015 (Windows, PS4, Xbox One)
• Fallout Shelter 2015 (Android, iOS, PC, PS4, Xbox One, Nintendo Switch) (a spin off Time Management game set in the same universe)
• Fallout 76 2018 (PC, PS4, Xbox One)

The result is an unusual way to dip into the Fallout universe. The cartoon style of the game matches the tutorials in the main game of Fallout and fans will recognise characters and creatures from those games but it's not necessary to have played Fallout to play this.