I think modern role-playing gamers aren't appreciate enough just how much folkloric precedent there is for "a random bunch of weirdos delve into subterranean vaults for treasures". So I thought I should share one of my favorite tales from German folklore on this topic - though there are hundreds if not thousands of further tales about this theme:
The Treasures of the Isholz
A long time ago, the Schlangenhecke estate belonged to the Morsbroich chapter house of the Teutonic order. It was as lively back then as it is empty and decayed now. As there are few inns in the remote countryside which provide food and shelter to wanderers, the farmer provided all the more hospitality. And in this manner, wanderers arrived at the Schlangenhecke who were admitted there for the night.
Once, three such guests requested the hospitality of the farmer. Because of their garb as well as their manner of speaking, they were recognizable as the inhabitants of a faraway region. The farmer offered the living room to them, and, after dinner, gave them fresh straw as bedding as was custom in the region. At midnight, the three wanderers rose up from their straw, quietly snuck out into the yard, and from there through a side gate into the outside.
But the shepherd of the estate had heard the noise and became suspicious: The strangers might plan to steal some animals, which he needed to prevent. However, he soon realized that he had misjudged them. But since he saw these people sneak out to the heath and towards the Isholz woods, he could not stifle his curiosity and snuck after them at some distance through this mild summer night. In this manner, he was able to avoid being noticed by them. The longer he followed them, the more his desire grew to understand what they were doing.
At the borders of the heath, close to the ill-omened forest, the men halted, whispered for a time, carefully looked around to all sides, and then ignited a candle. The shepherd was greatly astonished when he saw the three adventurers descend into the earth with their light. Initially, he circled around the spot from a distance. Then, becoming brazen, he went straight to the location where he had last seen them, but he could not find anything other than a rabbit warren from which not even the slightest noise emerged. He was overcome by considerable dread by this revelation, and quickly fled from the ill-omened heath into the safe refuge of the Schlangenhecke.
The next morning, he told the master of the house about this strange incident. The latter then questioned his guests, who had returned unnoticed at dawn. After much evasiveness, he finally received the confession that they had undertaken this long journey because of the treasures which were buried beneath the heath. They had dared the incantation, and, under its influence, penetrated the earth which had retreated before them. They then described how they had passed through a narrow opening into long corridors, which had opened into a succession of caves. In these caves, they had beheld glittering weapons, shining crowns, chains, and gemstones, and an abundance of precious metals in both minted and unminted forms. But they had been unable to touch anything at this time. They confessed that the retrieval of these treasures would have to wait for another, still distant hour.
As can be imagined, such news of enormous wealth caused receptive people in the surrounding hamlets and villages to seek their fortune there. And thus, treasure hunting is not a wholly unknown art in the region, although it has rewarded the practitioners little.
Years ago, a group of determined young men conspired together to quietly acquire everything needed for the lifting of subterranean treasures. Then they went out to the Isholz on a night which was favorable to treasure hunting. Their arts of invocation were indeed so successful that they could penetrate the earth after some digging. The men - allegedly seven in number - soon found themselves deep beneath the ground in long, dark corridors, which they were barely able to illuminate with their blessed light.
Finally, they trotted into a spacious cave, whose walls and curves reflected the rays of the blessed candle in a strange manner. In the center they saw a naked maiden reclining on a large stone slab as if it was a bed. Her arms and chest were richly adorned with golden chains and bracelets, and golden brooches and shimmering gemstones sparkled from beneath her dark curls. At the feet of this female apparition, there was gold and silver in all sorts of coin types in huge chests, and large containers, bowls and shields made out of noble metals, and crowns adorned with marvelous jewelry were piled up. The maiden waved to the treasure hunters in the loveliest manner, and elaborated that each of them was free to grab into the gold-filled chest with both hands. However, then one of the seven would be required to stay with her in the cave. Then the beautiful woman looked at each of the men in turn, as if she wanted to pick the one who would have to remain behind with her in the mountain.
No matter how bright the money shone into the eyes of the young men, no matter how marvelous the glitter of the gemstones reflected all colors and penetrated their greedy hearts, everyone was nevertheless overcome by the thought that he might be bound to this gloomy cave forever. The luring maiden might be secretly a monster, who in this moment might smile in a heavenly manner, but in the next could torture him in the form of a dragon. In this manner, they might race into the arms of the Evil Enemy, and be lost for all time!
Everyone thus carefully looked to the entrance of the cave, and used this opportunity to hurry away. As no one wanted to be the last, all seven rushed upstairs through the narrow entrance at the same time. They collided with each other, tumbled because the light went out, rolled over in their haste, climbed over each other, and finally all arrived up in the open air, though they were very scratched and disheveled. But no one dared to rest there. Everyone ran towards his abode on their own, and was in terrible fear, and they felt as if a thousand giant hands were grasping for them out of the darkness. Everyone reached their home with the firmest conviction that at least one of his comrades, if not all of them, were now buried within the mountain forever.
This misapprehension was only cleared up the next day. Every one of the companions became disgruntled and regretted that he had not brazenly grabbed something from the chest, and then the choice of the magical woman would not have fallen on him but on one of his comrades. Everyone reproached himself because of his fear and timidity, although the fellowship was unable to agree to a second expedition and treasure hunt.
Thus, the treasures of the Isholz still remain under the custody of the beautiful maiden or some other member of the spirit people. Therefore, a bold treasure hunter can still get lucky here in a twofold manner.
Source: Waldbrühl, W. v. Die Wesen der Niederrheinischen Sagen. 1857, p. 17ff.
If you know of any other good treasure-hunting tales, feel free to share them!
Yeah, it has something of a learning curve, but it is flexible in a way that few other tools can match.