Non-combat level advancement

Level-based character advancement systems suck. I'm beginning to think that this is because they usually only offer one dimension of character advancement. Everything has to be shoehorned into that system. Either it makes you slightly better at fighting, or it's associated somehow with making you better at fighting, or the rules ignore it. You move up a level, you float around in limbo, or you die.

This is usually portrayed as a problem with awarding experience. True, the DM can be told to arbitrarily award additional "roleplaying" experience points. While it's nice to be recognized, this isn't a very good solution. Among other reasons, if a player's style involves a lot of roleplaying, combat-avoidance, and creative thinking, then they get a lot less out of additional experiences points than a pure hack-and-slasher does. Roleplaying experience points amount to the minimum you can do to address the problem. 

So why don't we measure combat advancement and non-combat advancement separately? 

It's exciting to think what separate non-combat experience points could do as part of a robust, unified mechanic. Instead of one "class" level, a character would have two, a combat class and a non-combat class, or "career." Moving up a level one's career could involve a better reputation, a higher social standing, more earning power, a higher standard of living, and generally more pull in social situations.

You could choose a career, just as you do an adventurer's class, that determines the details of the advancement. Of course, some careers would have level limits. No matter how good a milliner or executioner you are, you're not going to become king. 

And yes, I've thought about skill-based systems, but I don't think those are the answer. Skill-based systems are too granular and choosing skills is a separate sub-game with its own pitfalls and complications. All you really need, I think, is the minimal differentiation between combat-based and non-combat character advancement.

First draft of career rules

There are two types of experience points: career experience points and combat experience points. Career experience points are awarded for good roleplaying or for spending time on your career in-game, or for other miscellaneous situations which involve no serious threat of death. Combat experience points are awarded for facing life-threatening danger. Career points are used for advancing in your career, and combat experience points are used for advancing in combat class, but not in career. Optionally, the DM may allow players to exchange career XP for combat XP or vice versa at a rate of 2 or 3 to 1. 

The profession, craft, knowledge, and perform skills, and the NPC classes, are gone, as are certain feats like leadership, replaced by careers. These careers include: craftsman, expert, gentleman, granger, hunter, merchant, officer, performer, scholar, servant, and thief, plus whatever prestige careers (like royalty or dungeon engineer) your game setting requires. These careers are broad. A burgher is a small-town shopkeeper, baker, or butcher. Expert covers most uses of the profession skill, hunter includes fishermen as well as trappers, granger includes orchard-keepers, farmers, and shepherds, and officer includes any organization with a hierarchy and meritocratic promotion: soldiers, sailors, public servants, and police constables. 

A character's career level limits the rate at which he can earn money, as well as the maximum amount of money he can retain between adventures. Sums in excess of this amount are assumed to have been spent on everyday expenses, like wine, women, and song. Career level also effects the number of followers and hirelings you can have. Each career has a number of career skills, for which one-half the career level may be added as a bonus to the skill roll.