[(E)]

In my main fantasy world I play with the concept of non-genetic races.
Orcs are created by a process "knowledge of the process to create an orc is not uncommon, however most people who know how to create them possess enough moral scruples to not do so"
The orcs take inspiration from Terry Pratchett's interpretation of them as well as a dash of Tolkien and Frankenstein.
Its also noted that those who create orcs almost invariably geld them in the process.
All the questions this creates are left to be explored in play should they come up.

Elves (at least in the central playable time period, but thats a side issue) do not exist, but "Elven blood" which is to say an elven ancestor does exist. This does not follow any of the traditional laws of genetic inheritance and anyone with it may or may not have any or all of the elven characteristics.