
Menace's Thief
This is my version of the Thief class for S&W Whitebox. Its not 1 to 1 with Greyhawk and the FMAG inspiration but has just a little bit of both.
Alternatively, if you want to make this more like OD&D's:
Increase Backstab dmg. multiplier by 1 every 4 levels
Attacking unaware targets have a +4 to-hit (in my games I just give advantage)
And give them, upon reaching 10th level, a 5-in-6 chance to use magical scrolls. On a failure the spell turns on them.
Otherwise I hope you guys like this little homebrew I made.