The races work hard to retain their individual culture, by creating niches in a larger society. Out of necessity it was found that all races can interbreed, but most keep their mating isolated to keep “pure” lines of their race and because (excepting some human half races) the pregnancy is extremely difficult on the mother. The child will generally take more after the mother,the pure lines take a poor look at any mixed parentage and generally refer to mixed offspring as mongrels. There are also still lineages that have traces of the outer plans; Aasimar and Tiefling.
Choose a race (or half) for your character.
The remaining races:
Aasimar, Dwarf, Human, Halfling, Tiefling, Drow, Orcs, and Goblins (Half drow and orc also)
Any race (other than human-half orc or human-half drow) are always considered full raced (for any ability purposes), but can have a descriptor to show their how their lineage was tied to another race (this will change how they are looked upon culturally, especially by purebloods of their race).