Tonight at Bethesda's E3 briefing, the company, Bethesda Game Studios director Todd Howard not only

The game launches tonight on iTunes as a free download. The game will offer some microtransactions for purchase, but Howard stresses there are no paywall times and you don't need an Internet connection.

Fallout Shelter lets you build your own vault and act as its "overseer." Basically, you control all the people inside the vault and must keep them productive and happy.

This includes sending couples into the bedroom, which "increases happiness," Howard said. As overseer, you are also charged with naming babies in your vault that are the result of this "increased happiness."

Howard went on to explain that Fallout Shelter was inspired by games like XCOM, SimCity, and FTL.

We'll have more on Fallout Shelter as it becomes available.