In 2004, when we started working on Fallout 3, the first asset we made was the power armor helmet. Even though the game would evolve over the following years, we knew from the very beginning what the essential elements were.
We toyed with ideas for the location, story, and themes, and then the art development started in earnest in late 2009. FALLOUT 4 STARTED SOON after the last DLC for Fallout 3 was finished.