Shadowrun? *Snickers* There's some theory going on, where Elder's scrolls and Fallout share the same universe, what with the Nirnroot being found in Brotherhood's Prydwen, the suggestion that Elders scroll came after Fallout, way way way after. Worth a note that it is a possibility, not a confirmation, for all we know, it could just be a simple easter egg. Regardless, what Raney said is right, you need not tie yourself into the current universe if you don't want to, if it works with a new universe, a new setting that the overhaul is done for, go for it! Speaking of which a shadowrun universe would not be too far fetched to tie into Fallout >.> <.< Just saying!