Here's a preliminary "large scale" map of the Kingdom of Vaquero. White dots are towns 3-4 days apart, mostly along major waterways and coastlines. Numerous smaller rivers aren't shown at this scale.
http://i.imgur.com/lTKpWFz.png
The wilderness is dangerous. Not exceptionally dangerous by DnD standards, but if you're one of the CR 0 commoners that make up 99% of the population there's a 25% chance that going for a trip on any given day will result in running into something that will kill you.
You're more or less safe if you never leave the farm or do so only in large groups of a half-dozen or so to take the crops to market after harvest, and even then farms tend to be clustered around walled market towns that the commoners can retreat to.
Agriculture provides most of the civilization's product, because successful hunters are by necessity more competent and therefore rare.
Still, a functional kingdom requires some degree of trade and travel and that's where adventurers come in. Only they are capable of facing the rigors of routine travel from town to town, city to city, collecting taxes, escorting officials, protecting caravans, and seeing to the needs of the smaller communities. The King does have his military and his champions, but they can't be everywhere at once.
Adventurers fill the gap.
Despite their obvious utility, Adventurers also tend towards being iconoclastic individuals who amass great deal of personal power. They're the heroes of legend. They topple tyrants and change regimes. They are a constant threat to the status quo, even if only in potential. As a result, in the past there have been frequent crackdowns on Adventurers to try and keep them in line... not just in the Kingdom of Vaquero, but the lands to the north as well.
This led to the establishment of the Adventurer's Guild. Not truly a single guild, its form is remarkably similar in every city where guildhalls have been established. Members pay annual dues and give the guild a share of their treasure in exchange for legal protections, lobbying power within local government, access to healing magic, appraisal, and a market for recovered treasure.
That's what I have so far. Thoughts?
This message was last edited by the user at 18:14, Sun 20 Nov 2016.