In this campaign setting it is possible to have more mixed races than just half-elves or half-orcs. The reason half-elves and half-orcs are not listed is they will follow the same rules as any other mixed race. The rules are fairly simple and I will lay them out as clearly as possible. This system allows players to create a character from just about any combo of player races, but it is fairly random in what you get.
The system works in this manner:
Get the parents of the character approved (This is already done if a previous character married)
If the parents were not married during the previous campaign select the race that will be the other parent. Or if brand new character with no tie to a previous character select the races that will be the parent races and assign genders.
Any attributes that the two share in common should be noted as coming from both
Now for each racial ability that the two don't share roll a d6. 1-3 is Father. 4-6 is Mother.
Note which racial ability you get until there are no more racial abilities. If one has more than the other you still roll to see if you get the ability or not.
Now select how you wish to appear.
You count as both races for the purpose of feats and any race related effects