On the Origins of Half-Orcs

I am taking one more break from continued posting about the Book of Adventure from the AiF rules to post this quick thought.

Half-Orcs have always been among the outcasts of society.  This only makes sense considering their typical origin.  Usually, the Half-Orc is the result of Orc conquerors and the obvious spoils of war.  More rarely, the Half-Orc is the result of of an "unfortunate" pairing with an unattractive human.  Neither one of these are satisfying answers to the origins of the Half-Orc.

I believe that there is a better explanation - or even multiple explanations - for the existance of Half-Orcs for three simple reasons.  First, the name of the game is fantasy role-playing so step out of the box and come up with some reasons out of the ordinary; skip the science and start thinking of magical, divine, or other reasons.  Second, I keep hearing how creative role-players tend to be. How about showing some creativity and come up with a different reason?  Third, most role-players I know of really enjoy tinkering with the rules.  Why let the changes be restricted to just the rules?  I can not count the number of times I have read that it is "your game" so why should I not tailor it to my liking?

In my campaign world Half-Orcs are pretty close to their official writeup in many ways except for their origins.  Here is what I did to change the Half-Orcs of my world.  Half-Orcs are not the product of crossbreeding - willful or otherwise - between a Human and Orc.  In fact, that union will never produce any offspring.  Half-Orcs are actually the product of divine intervention.  At the end of the First Age of my world, there was a great war. All nations were eventually pulled into this conflict and even the Gods took sides.  There was one spot where war was expected but both sides refused to give in to the conflict and the will of the Gods.  The capital city of one human nation and the nearby Orcs had a truce that had been in place for several years by the time of this war.  They both saw the needless bloodshed of the past and did not want it to continue.  The Humans and Orcs from these two areas made a stand against their respective allies and against the Gods even.  As punishment, the Gods cursed these two societies by forever joining them in mind, body, and spirit. The other cultures started calling these people and named them as "Half-Orcs" and the label stuck.

There it is - the quick version of the origin of the Half-Orcs in my campaign.  I just did not like the "official" explanation in the rulebook.  It did not seem that enough of these beings would be created from the implied explanation to justify an entry in the races section.  I just sat down with my notes and tried to draw some logical conclusions.  That is the one I came up with and used.  Do you have anything like this in your game?

edit 1 - removed unnecessary "an".