My fighter/thief attacks from behind the back of enemies constantly and she scored very few backstabs over the course of my Dark sun 1 playthrough (maybe 5 to 10 and I'm generous). Currently just started Dark sun 2, and you guess it, ZERO backstabs so far.

What am I doing wrong?
I read some comments that you need to backstab from the opposite side of the side that you attacked. Huh? With another character? Meaning I can only backstab after my other fighters have landed their first attacks?

Does that mean that in any battle, if the fighter/thief moved first she will never be able to backstab no matter from what position she attacked the enemy?

Please enlighten me.

I only played Wake of the Ravager once, and I remember that backstabs in that game were SO finicky that I eventually gave up on trying to do them. >.< It's a lot easier in Shattered Lands where if you're attacking from behind the enemy, it will almost certainly be a backstab.