xKrypt0 said:Red dead Undead Nightmare was sold as a stand alone disc - yet here it seems to be suggesting as a digital game you have to own the original - bit odd that.
There is a way more listed here than there is on the actual Microsoft site's sale page I note even taking into consideration you have to wade through more pages to find them.
Because it was also offered as DLC to the main game. GTA IV's Episodes are the same way.