You people need to learn difference between CLASS and BUILD.
Please, enlighten us.
You can start with the example already given of a character who sneaks around and whacks people with a Bound Greatsword, then raises their bodies. You've already asserted that there are only three classes, but it is not clear to me which class this character is. Is he a Thief because he sneaks around constantly? Is he a Warrior because he whacks people with giant swords? Or is he a Mage because he uses Conjuration skill heavily?
I'm also curious as to the source of your assertion that Warrior, Mage, Thief is the definitive Blessed Trinity of classes. Why three? Why
these three? What are the hard dividing lines that allow you to distinguish one from the others and what happens when you encounter a character who doesn't fit neatly into one (and only one) of them?