Apparently, Darkhen Rahl raped Richard's mother and Richard was concieved. But, in Wizard's First Rule, it says that Darkhen was a child when the boundary goes up. They are not specific about his age, so he may have been old enough, but in Debt of Bones it is made clear that Richarrd's mother is a little girl when the first boundary goes up. She is definitely too young to concieve. So, when does the rape take place?