The City of Goodwill
The most common story explaining the creation of the vampiric race is the Biblical Cain, who killed his brother, and was cursed by God. Caine, being the first vampire, was the most powerful. His childer were less powerful, and so on. The measurement of a vampires realtive power, and distance from Caine, is their Generation. The Generations range from 1, Caine himself, to 15, the final generation of vampires.
As a vampires Generation gets higher, the curse of Caine becomes less potent in their blood. Some vampires, regardless of Generation, feel the Curse of Caine more lightly than others. These vampires are called Thin-Bloods. They find it harder to use disciplines and sire childer, and impossible to sustain ghouls or create blood bounds.
Thin-blood is rare amogst vampires of 13th or lower Generation, but still possible. About half of 14th Generation vampires are Thin-Blooded, and all members of the 15th and final Generation are Thin-Blooded.
The Thin-Blood of 15th Generation vampires is much stranger than that of any other Thin-Blood. It is said that 15th generation vampires are close to being human, able to withstand some sunlight, able to digest food on occasion, and even bear children/impregnate a mortal. These initially thought of children are known as Dhampirs