- You've grown up in a literate, relatively civilized society.
- Within this society, there is a significantly large criminal underworld, which all criminals are intimately familiar with.
- Your character has to have been intimately familiar with the slang of this criminal underworld.
- It is impossible for any other class to reach your level of familiarity with the slang of this criminal underworld.
Now here are the restrictions that the mechanics of a Fighter puts on me;
- You are skilled with weapons.
These are not comparable restrictions. A Fighter puts almost no restrictions on my character; a Rogue puts many, many restrictions on my character.