Bethesda launched a surprise mobile title, Fallout Shelter, at their E3 showcase today.

Separate from upcoming behemoth Fallout 4, Fallout Shelter is a simulation/strategy game inspired by the likes of FTL, The Sims, and XCOM's base-management component.

Featuring a 2D art style similar to the main games' Pip-Boy cartoon graphics, Fallout Shelter expands the lore of Fallout in an intriguing way, offering players a chance to create their own Vault to house and/or torment survivors.

Players will excavate and build nuclear shelters for Vault Dwellers to live, work, and love in. Managing a range of resources and room types, they'll have to keep their citizens healthy, happy, and safe from raider attacks.

Each dweller has their own stats, and can be sent on missions into the desert, socialise, and reproduce, ensuring a long life for the human race (until some guy called Gary clones himself and takes over the vault).

The game is out now for iOS, and is free to play, with no paywall timers or mandatory internet connection.