Ghoul

Prolonged exposure to the effects of background gamma radiation—part of the fallout of the Great War—can spontaneously mutate humans. You are one of those mutants. Either slowly, or strangely spontaneously, your body changed into that of a rotting, living corpse. You no longer age the same way and appear unaffected by radiation. Your skin peels from your flesh but seems to be sustained by your mutated metabolism.
You are a “ghoul”—a necrotic post-human—one of many rag-tag survivors who weren’t lucky enough to get into a Vault-Tec facility. You may have been born after the war, and over time developed the necrotic mutation. You may have come from Vault 12 in Bakersfield, California, whose vault door did not close, exposing the population to the radiation from outside. You may have taken refuge in a ghoul settlement, like Underworld in the Capital Wasteland, and have ventured out recently to explore, scavenge, and survive.
Civilized ghouls, such as yourself, also fear a possible degeneration into a frenzied, feral nature. Feral ghouls are necrotic mutants like yourself who have lost higher brain functions and reverted to a primal, violent state. They attack non-ghouls indiscriminately to defend their territory or feed. Whether this loss of reason is due to acute levels of radiation or the inevitable outcome of the mutation, you’re not sure, and that makes it all the more terrifying.

Trait: Necrotic Post-Human

You are immune to radiation damage. In fact, you’re healed by it—you regain 1 HP for every 3 points of radiation damage inflicted upon you, and if you rest in an irradiated location, you may re-roll your dice pool when checking if your injuries heal. In addition, Survival becomes a Tag skill, increasing it by 2 ranks.
Your age at a much-decreased rate, and you’re probably older than your unmutated companions—you may even have survived the Great War of 2077—but you’re sterile: “the first generation of ghouls is the last” as the saying goes. You may face discrimination from “smoothskins” (humans who aren’t ghouls), increasing the difficulty or complication range of Charisma tests depending on your opponent’s beliefs.