The story of New Vegas, like that of any other post-apocalyptic adventure game, starts with a nuclear holocaust. All life on earth has nearly ceased to exist as the radiation bombards the surface of the planet killing off everything in its path and creating a barren world of irradiated dead bodies. This includes all of humanity's major cities as well as most of the living creatures upon the surface of New Vegas. One of the last human survivors, courier traveler Oscar Ace Murphy, stumbles into the town of New Vegas and stays for almost a week, searching for a way out of the place.

While in town, he bumps into a mysterious stranger who tells him about a secret group of scientists called the arers. These scientists, led by Doctor Donation, are trying to develop a drug to cure most if not all of the radiation damage done to the city by the nuclear war and, in their endeavor, they have recruited some locals like you to test their product on the human population. When these tests show promising results, the testing is expanded and, using parts from doctor donation's database, is made available to the general public.

With the testing completed, a military unit called the Vegas Research Station is established as a research wing for this new drug called Xenol, which is intended to cure most or all of the effects caused by the radiation leakage. Without much choice, the scientists are forced to help the government in suppressing any negative publicity regarding Xenol, so a force of little soldiers called light armored shock troops are secretly placed around the city. When you complete the original New Vegas Redesigned 2 Modified questline involving the first outbreak of the disease, you get to choose whether to kill these soldiers (and be rewarded with a speech to the effect), or recruit them as part of your new team. Although it may seem that the game is going out of date, the revised edition adds new content and a whole lot more, such as new apartments to buy, a whole new city to explore and, best of all, the value for money is much greater.