Half-Breed Sentients

Half-Breeds are species such as Hobgoblins, Dhampir, or Tieflings, any race that is comprised of two or more halves to make a new whole.

The Rule of Eight

The Rule of Eight says that with no exceptions, it takes eight generations for a half-breed's lineage to fully move one way or the other, and eight generations of no changes to create a new race entirely. The most commonly used example is Half-Elves, since they are the most common sort of Half-Breed in the Empire.
If a human mates with an elf, the child will be a half-elf. If that Half-Elf mates with a human, the child will be a Half-Elf. This continues until the eighth Half-Elf in the line, who's offspring with a human would be human, with no exceptions.
The lesser known Rule of Eight regards the Gwelin and the Jianro and a few others. In the case of the Gwelin, Half-Elves mated with Half-Elves exclusively for generations, eventually resulting in a new race entirely that leans Elvish. The Jianro were also once Half-Elves, but over the generations became a new race that leans Human. By most ways of accounting, the Gwelin are elves and the Jianro are humans.

Spontaneous Half-Breeds

Spontaneous Half-Breeds are the result of supernatural or scientific influence. A Spontaneous Half-Breed always has two parents of the same species and by definition can originate with any sentient species. Tielflings, Aasimar, and Skinwalkers are all Spontaneous Half-Breeds. Those who make a study of the races often compare these races to sorcerous bloodlines.

Type

Natural