|A Noble's Land by Emily Fiegenschuh|
NPC classes are a mixed bag. Some people prefer that anyone of importance be statted up with actual class levels, meaning that noble lord is actually a Fighter 4. Others enjoy NPC classes as it makes player characters a cut above the average soldier and spell slinger. The 3rd edition DMG for me, and possibly many, was when I first began to consider the rammifications of NPC classes. By assigning weaker levels you ensure that some people have more than a d6 (well d4 for a commoner) of HP, meaning your scheming noble might actually survive the arrow from the impatient player. Their bad attack bonuses meant they were pretty lousy in a fight and if used consistently it meant the Fighter classes with their full BAB could see just how much more skilled they were (although they would still have their ego crushed by spell casters in double digit levels). A few people advocated giving each character a 0-Level NPC class to represent who they were before they took up the adventuring mantle. Not a bad idea but the NPC classes weren't particularly balanced (or meant to be) so your options boiled down to extra attack bonus, piles of gold, or even more skills, or the woeful commoner. Although I once had a DM that would only allow Spellfire if you played as a commoner.
Star Wars Saga Edition has one of my favorite ways to adjudicate NPCs called the mook rule, or perhaps more appropriately the Storm Trooper rule. Any regular guy acquires Non-Heroic class levels which are drastically inferior than a character class (although there are a few tricks to make them useful to a numbercrunching player) but their progression is uniform and each of their levels is worth only 1/3 of a PC's threat level. So it takes a third level non-heroic to be a match for a first level heroic. I like that PC's start out heroic and I like that the system enforces that since most people they will be facing are mechanically just as bad as a storm trooper. Named and important characters are of course statted up just like a PC.
The major issue with NPC's is time constraints on the Game Master or Judge. 3rd edition is particularly heinous for this crime since there are a painful amount of boxes to tick and numbers to roll forward at each level and creating an NPC character rather than flipping through the monster manual takes exponentially more time. Saga is much lighter in this approach as their feats and talents are very much balanced and many do not require you to preplan what feats you are working towards (little to no pre-requisites are a good thing!) but if given enough splat books you can spend an hour or even more just working on a single character ironing out all the extraneous details. You never know when your Sith Lord might need to make a Knowledge(Beauracracy) check.
Looking at all this we want NPC's to be quick to generate, and they shouldn't be powerful enough to step on the PC's toes unless they are an archvillain or a suitably important piece in the world. They should not be a complete pushover but should not possess to great a challenge; hero's do need to whallop minions and henchman from time to time. Here is what I've been considering which should address the two major points. Since each character class is intended to have a full range of thematic abilities at level 1 each class is rather diverse. As we discussed before the Magic User is one part spell caster and one part elementalist. Another class may mix samurai and scout, another may mix commander and soldier. An NPC then is good at one of these things but not both, that alone is reserved for our illustrious multi-talented PCs. They may study spells or they may shape the elements but not both, they may lead or they may fight. For quick generation the NPC could either use a PC's single class feature, or instead they have a watered down version. If each ability has three clauses (primary goal and bonus or extra conditional abilities) then the NPC would only have the primary goal. This is a good thing since the Judge controlling the NPC doesn't have the focus to recall all aspects of a PC's ability at the drop of hat let alone multiple ones.
I haven't done any playtesting on this yet, character classes are still being finalized but I think the idea has promise. The question remains, will it actually fulfill the goals of time saving while retaining enough mechanical complexity to keep them interesting.