A new class that might work best for NPCs, the spy! This is first draft material.
Spy
Requirements: Minimum CHA 9, DEX 9
Prime requisite: INT
Hit Dice: 1d4
Maximum level: 14
Armour: Leather only, no shields
Weapons: Dagger, club.
Languages: Alignment, Common, Code.
Code
All spies know one code which they made use to encode and decode messages. From 4th level they have an 80% chance to understand other codes given an appropriate amount of research time for the difficulty of the code.
Disguise
Spies have the same disguise ability as the Assassin class.
Extra languages
Spies gain an extra languages as they advance in the same manner as the Bard class.
Spy skills
Spies have the same Climb Surfaces, Hear Noise, Hide in Shadows, Move Silently and Pick Pockets skills as a thief of the same level.
After Reaching 9th Level
A spy who has reached 9th level may establish a spy guild attracting 2d6 level one spies to work for them.
Spies use the thief progression table.