Thanks to maddoctor and Teratus for their technical explanations. My original thought was purely technical in nature, but poorly worded. I should have included a lot more explanation of what I was wondering. It left too much room for misinterpretation. My original thought was that during character creation you pick race, gender, height, face... etc (don't remember exact order). After gender you are limited to things specifically programmed for that gender and race. Why couldn't you just do race, height, face.... and allow the user to pick out of all the gender options at each point. So if there are 5 male faces and 5 female faces, then when picking faces you would have the option to pick from all 10. You would still be able to create the character of your choice, just with more choices at each step.The answer would appear to be that the underlying way the character's have been created is the reason. There is a male and female skeleton/mesh that work differently to help give the feel of gender (it is the best explanation I have heard so far).