The Xbox One will become fully backwards compatible with the Xbox 360, Microsoft revealed at their E3 press conference today.
100 titles will be available for the feature by this holiday season with more to come. The announcement was accompanied by a demo of Mass Effect being played on the Xbox One rather than 360.
It will also feature cross platform multiplay, meaning that you can play Xbox 360 players online via the Xbox One.
This feature will be available by holiday 2015 and you can find an initial list of compatible titles here.