Nobody knows where dungeons come from, or for what reason they exist. It has been postulated that they are created by an evil God as a means to torture and kill, with the promise of treasures used as a mechanism to encourage victims to enter willingly. It's equally been suggested that they are a providence from a benevolent God, with monsters and traps included due to some divine agreement between Gods that gifts may not be freely given. Other theories include that they are important for the circulation of mana, or that they are simply the whim of some bored and powerful being somewhere that fancied some entertainment.

- An excerpt from the entry on dungeons, from a copy of Adventuring for Dummies found in a legible condition in the ruins of an unnamed village.

In the darkness and silence, under featureless rock and earth, there was a flicker of change. Something new stirred under the ground, shifting dirt and burrowing into the stone. A tiny hollow formed, at its centre a perfectly round crystal, no larger than a grain of sand and glowing a faint blue. Those who had the senses to perceive it would have seen the mana in the area shift and flow towards this crystal, then pulse back outwards settling into the stone around the hollow. The hollow started to expand. It formed edges and flat walls sitting at right angles. In this perfect cube a pedestal of stone rose in the centre. The glowing crystal, already doubled in size, sat atop. Not just a crystal but a 'core', and not just a hollow but a 'room'. This was the birth of a new dungeon. Text floated in a loop around the dungeon core, despite the lack of anyone to read it.

Unnamed dungeon
Floors: 0
Mana: 10/10 (regeneration 1/hour)
Dungeon Points: 0
Available monsters: slime, giant leech, dog
Available traps: tripwire, spikes, pit
Available loot: copper coin, red berry, green berry
Available skills: Spawn, Absorption

Although too young for complex thought, the dungeon was born with innate knowledge and a useful set of instincts. It knew to expend its mana to construct its first floor, assimilating stone into a part of itself, hollowing out rooms and placing features. It knew some simple strategies, such as placing tripwires across room entrances and hiding monsters around blind corners. It knew that once it had a viable first floor it needed to open up a passageway to the surface, to attract wildlife and adventurers. It should try to kill and absorb these invaders to earn dungeon points with which it could purchase new features. It had the instinct to grow, to create hundreds of floors and dig down into the depths of the world. It also knew the Rules; that it must provide a path from the surface to its core, that floors should exist on a two dimensional plane, and that it couldn't make alterations to a floor with active invaders present. And so it worked to build, to assimilate the local stone, to draw on the ambient mana in order to build some more. And at last, once it was ready, it breached the surface and waited.

And waited.

As months rolled into years, the fledgling dungeon finally started to sense that something was wrong. In all this time, not even the smallest insect had crossed its border, nor was a single seed carried in on the wind. Had it not properly opened up its passage to the surface? Maybe it had just breached into a sealed natural cave? That would put it in violation of the Rules! Slightly panicked, it pushed its mana out towards the entrance, assimilating the surrounding stone into itself.

Dungeons do not possess eyes or ears in the conventional biological sense, but are able to perceive around themselves via the mana infused dungeon stone that makes up their 'body'. Assimilating the stone around the entrance gave the dungeon its first look outside since its birth, and what it saw was a hellscape. Churning smoke blacked out the sky. The ground was bone dry and cracked. There were no signs of life; not a single plant nor animal.

Reassured that it hadn't accidentally broken the Rules, the dungeon calmed back down. The reason it hadn't had any invaders was simply because there wasn't anything around here to do the invading. Although slightly older now, the dungeon still hadn't gained much knowledge beyond what was innate at birth: Normally an accumulation of knowledge would come from observation of the sentient life that invaded it. But its innate knowledge and intuitive intelligence were sufficient to work out that if there was no life here, then perhaps it could move its entrance elsewhere? Its instincts told it that the entrance should be a short straight path from its first room, but that obviously hadn't worked out. Perhaps, rather than 'short' in an absolute sense, it should be relative. 'The shortest possible that achieves its purpose.' Then the dungeon needed to find the closest source of life. It began assimilating the surface radially outwards, compacting dirt down to dungeon stone as it went. Taking over the surface was something else that its instincts were very much against, but it was necessary. Instincts would just have to be ignored so that it could serve its intended purpose.

More weeks passed. The dungeon had now taken over a patch of land that was kilometres in diameter, yet had still not found a single living thing. It had come across bones and debris that made it clear that there was some form of life here once, but that didn't give it any clues as to where they had gone. It wasn't until a month after it began expanding that it made its first significant find; the remains of habitation, a ruined village. More bones littered the street and houses, some seated at decaying tables still set with plates, although the contents had long since perished. Very few bones lay in the remains of beds. Whatever happened here happened in daytime, too quickly for any reaction, and too broadly for any looters to have visited since. The dungeon did have some innate knowledge of furniture, but not the wit to deduce the fate of the village. It did, however, recognise that it wasn't going to solve its problem of a lack of life by expanding; obviously everything around here was already dead, and the power of its core was insufficient to control mana much further out than this. With a rustle of mana that could have been the dungeon equivalent of a sigh, it absorbed what it could from the village, treating it as it would debris within the dungeon.

New loot unlocked: Silver coin

This was new. Some sort of text scrolled in a circle around the core. Language was included in the innate knowledge of the dungeon, but it was unable to comprehend the meaning. It did however sense a change within itself, and further inspection revealed that it had a new loot option available. Producing the new coin it noted that it looked very much like some items it had assimilated from the village. The text had popped up once it had assimilated the fifth such coin. That was an interesting discovery; it could unlock new loot items by assimilating several existing examples. Then why had it only gotten silver coins from the whole village?

Silver was naturally more resistant to the decay of time than rotting wood and rusting iron, and this village was neither large nor prosperous enough to contain further items that had withstood the test of time. But the dungeon could not recognise differences in material or condition, so had to abandon this mystery.

In any case, unlocking a new loot item wasn't important. There was nothing in the village to grant dungeon points, without which it could not buy new floors. Perhaps if its core were stronger it could expand further and find something, but strengthening its core would equally take dungeon points. It was trapped; with no dungeon points there was nothing it could do to create more dungeon points. With its budding intelligence, the dungeon pondered.

It could just sit here forever, doing nothing. The lack of invaders meant it was in no danger of having its core attacked and the instinct to grow was at least partially for protection. Having its core buried under 100 floors of vicious monsters and fatal traps was far safer than having it just under the surface behind a few weak slimes and traps that were at best on the level of a nuisance. But even if it was safe, it was... bored? Could a dungeon be bored? Perhaps a better word would be lonely. It wanted to watch adventurers testing themselves against it; the strain of battle, the excitement of finding treasure, the sadness of the death of a comrade. The dungeon considered using its own monsters, but while they would accept orders to attack a single target, they wouldn't understand an order to invade the dungeon. Perhaps if it had enough dungeon points it could purchase some intelligent monsters, and put together its own adventuring party?

But now it had come full circle. To earn dungeon points, it was supposed to kill invaders, of which it had none, or it wouldn't be thinking along these lines in the first place. It didn't matter what the invader was; even the weakest slime was a viable target. Then what separated an invading slime from a slime created by the dungeon? Back in the dungeons first floor the ceiling of a small room caved in, crushing a couple of giant leeches. No points were awarded. But it had earned new loot from the village without expending points, so there must be other loopholes available. Maybe it was possible to earn new monsters and traps in similar ways? Ignoring its instincts that were insistent upon a minimum spacing between trap placements, the dungeon placed some spikes at the bottom of a pit.

New trap unlocked: Spiked pit

The text again! The dungeon felt a new trap type unlock and knew the experiment had been a success. Then could it be improved further by hiding it? The dungeon grew a coating of stone over the top of the pit, thin enough that it wouldn't hold much weight.

New trap unlocked: Camouflaged spiked pitfall

Another success! But how could this be applied to monsters? An attempt to spawn a slime and dog on top of each other just resulted in the dog drowning inside a confused slime. An attempt to summon a dog on top of a giant leech was... messy. The dungeon pondered again as blood and viscera were absorbed by the floor. And walls. And ceiling. A slime normally cost 2 mana to summon, but what if it deliberately forced more mana into the summoning?

Error: Attempted to summon a monster too high level for this floor.

The coalescing mana suddenly burst apart, causing the dungeon a burst of pain. It could comprehend the problem, but despite the apparent success in almost unlocking a new monster, it knew it had hit another dead end. After all, creating new floors required dungeon points!

The dungeon again considered how its own monsters differed from the life that should have been outside. Dungeon monsters didn't need to eat or sleep, living off the dungeons ambient mana. For that reason they couldn't leave the dungeon. So what if a dungeon monster started eating physical food? The dungeon spawned in some berries and had a dog eat them, before trying to send the dog out through the entrance. The dog immediately crumbled to dust once it passed the perimeter. Another failure. It thought that perhaps things would be different with outside food instead of dungeon food, but yet again, it was because nothing like that existed that the dungeon was in this mess to begin with.

Alternative options exhausted, the dungeon tensed up. It only had one more option it could think of; it would have to be naughty. It would have to bend the Rules.