Anyway, before I go off an a tangent about Palladium games, the point I'm trying to make is that BRP's default treatment of non-human player characters dovetails nicely with what I intend to do in my Freed Lands campaign: start with human characters only, but keep open the option of introducing non-humans as the campaign progresses. My plan is for the initial setup to involve a group of human outlanders, probably all Brinthine, entering and exploring the newly accessible region of Morbenhann for the first time.
Part of my intent with Freed Lands is to avoid making it "D&D in another system", so I try to make setting elements at least somewhat plausible. More accurately, I don't want at any point to say "a wizard did it" to explain anything unusual present in the setting. Still, I can't shake my Palladium-bred love of having lots of intelligent species running around in a fantasy campaign. The compromise I came up with was to indulge my own tendencies towards quasi-scientific speculation, so I try to come up with ecologically and evolutionarily plausible explanations for things.
For example, instead of having your usual orcs created by an evil god rampaging across the landscape because they were born that way, I've got wheruls, a sapient, reptilian race descended from tree monitors that were forced onto the ground when a climate shift changed their habitat from forests to savannahs. Seeing over the tall grasses that subsquently covered the plains meant that they began to stand upright, freeing their front legs for other uses, and eventually you've got an exploding population of lizard men who need more food. My goal is to create similar backgrounds for the other "races" of the Freed Lands setting - dwarves, ogres, and hulderfolk. (Elves don't count, because they're magic. Yes, I realize that contradicts the whole point of this entry.)
Ultimately, I realize that this approach doesn't produce results that are especially realistic, from a scientific point of view, but I find it a satisfyingly different angle from which to attack a "classic fantasy" setup. Since worldbuilding is something personal, that's enough for me.