
This is because it was not made by Bethesda but by Obsidian, a studio known for such titles as Knights of the Old Republic 2, Alpha Protocol and more recently Pillars of Eternity. Despite being powered by the same technology and having very similar graphics, it’s also designed in a very different way. New Vegas might at the first sight look like just another expansion to Fallout 3 (it uses the same engine and a lot of the same graphical assets) but it is in fact a separate full-length game.
