Tapped Potential
Early in their careers, most adventurers end up venturing into a low level dungeon. Some place full of goblins and giant rats with small amounts of treasure that seems small to the greedy adventurers but would be a fortune to a group of commoners. Which makes you wonder why, in a world full of other desperate adventurers, there remain low level dungeons that haven’t explored. Or why a group of twenty commoners haven’t rushed into the cave or old mine as an irate mob to claim the treasure. It’s not just that previously explored dungeons seldom exist, it’s that they never exist. The players never, every arrive at the barrow of the dead king to search for rumoured loot and find fifty years of treasure hunters have been there first, digging up the place and stealing anything that hadn’t been nailed down. Instead, no matter how accessible the ancient tomb, the players are always the first living souls to venture within.
I’d add an exception: Undermountain.
Been there several times, as most of us, and I’ve seen several PCs die there… during our last trip, the whole group got killed, leaving all their treasure there. It’s a well-known and explored dungeon, but also a meat grinder. Actually, most of the treasures you can expect to find there once belonged to previous adventurers…
Anyway, I usually place some nasty traps to guard the first sections of an “unexplored” dungeon, and have the first one or two carry hints of their presence, in the form of the remains of would-be plungers who got grisly slain. Commoners getting to see those usually take the hint and leave…
When I was a kid, I always got an impression that dungeon adventurers are kinda normal and civilization accommodates their needs. Cities allow them to walk around in public well-armed and fully geared — a privilege typically only for the ruling- or warrior-classes. No one challenges them on where they get the treasure, even though most of the time it was plunder, nor would nobles or head priests accept people “selling” them relics that where already stolen from them. People always asking them to find some lost person or item. High availability and low cost of arms & armor (more so, swords and mail). Cost of common items set ridiculously high due to the high influx of gold, silver & copper, with more historically common coinage (brass, bronze, etc.) being so worthless, no one uses them at all. Whole gods that cater directly to different adventuring classes, with few gods usable by the common man. And so on and so forth.
The only thing that makes sense — besides the super-inflation of common goods — is the fact that high-level Fighters are allowed by local rulers to build a keep on the edge of civilized lands, if only to keep them FAR away as to not be a threat to their rule, much like scheming Roman rules who send popular Generals off to garrison far-off territories.