Dear LordMiller and yammahoper,
Thanks for the info. I somehow tend to disagree with the idea that such a system is only setting-based, it is also a question of game-balance (but I have been playing D&D 3E too long, so maybe I am too obsessed by the later) and therefore I think that guidelines about this belong in the core rules.
For example, if I want to design a balanced encounter for my Level 10 player group and I throw a bunch of medusas at them, how many shall I use? Two, three, four?
I can use the level of medusas to estimate how many of them my group of players can shoulder, but does this information (i.e. virtual level of a medusa) assumes character with no magic items at all (and therefore I can throw a couple medusas more at my players if their characters have powerful magic items available)? Or does it assume characters with a value of "Level x [number] gp" (and I should be wary about sending so many medusas if my players never got any magical items so far)?
This kind of guidelines or information is necessary to design balanced encounters and to help the GM design treasures appropriate to the level of their group... Or at least that's how I have started to think since playing D&D 3e.
If I take a setting-only approach and compare the yearly salary of a craftsman to evaluate how much the town mayor will pay to get rid of the nearby tribe of kobolds, maybe he will offer the heroes 10 gp or 30 gp? But what they can buy from that is ludicrous... It is not even enough to procure an hemorrhage-stopping herb.
So reconciling setting economy and heroic treasures usually does not work (as the D&D rules show), but my hope had been that there were at least some RM guidelines to harmonize character levels and virtual wealth (as represented by magic items).
Sure my players will get their mithril sword after they killed the Demon that guards it. But shall that be a Type III or a Type V Demon? Shall I confront them against him at level 10 or level 20? Etc.
I guess my best bet is to use the treasure codes in the creature entry and always stick to that, hoping that, in the long term, randomization will even out aberrant results and the extra power my group gets from items will be "appropriate" to their level... I guess I just like the idea of having a convenient table that gives me indication as to what is appropriate for an average wealth at a given level.
Bocklin