During E3 Bethesda and Microsoft announced that people purchasing Fallout 4 would get a downloadable copy of Fallout 3 for free with Xbox One. This is made possible thanks to the backwards compatibility revealed during the very same event.
Now this has been further explained over on Xbox.com:
<I>Through February 8, 2016, purchase Fallout 4 and receive Fallout 3 on Xbox 360. The code for Fallout 3 will be delivered to your Xbox message center in 7-10 days. Redeem your code on Xbox One or Xbox.com. Fallout 3 will be backward compatible so you can play it on Xbox One starting November 12.</i>
Our review of Fallout 4 is on the way, so tune in later today to find out whether Bethesda has delivered another post-apocalyptic classic.
Thanks, Dual Shockers