Once upon a time a god created a universe, as gods are wont to do. The god created fauna and flora and added mana to the world. Not everything got mana - in fact most things didn't - but what did, excelled.

The god made some of the creatures sapient, and - while none of these had mana - they excelled as well. The sapient species excelled so well that they quickly claimed the top of the food chain.

Each time the god created new life they used up a bit of their power. As a god they had a lot of power, of course, and they saw no reason not to use it. A god had to have a world, and good worlds contained life.

For a while the god was satisfied with the world and its 8 sapient species. But 7 of the sapient species slowly grew bored of their luxurious life as a top predator and began to grow greedy for more. To not just be among the best, but the best instead. And as the sapient species had placed themselves firmly on the top of the food chain, the only way to gain more dominance was to dominate another sapient species.

6 sapient species turned to the 8th species - the only species that didn't desire to dominate others simply for the sake of it - and began to kill and capture any they found. A couple of centuries later, only 7 sapient species remained.

The 7th species wanted more dominance as well, but found it easier to pick on a race rather than an entire species. The 7th species had 7 races and one disliked fights and conflicts more than the others, which made it an easy target for bullying and abuse. After half a millenia, only 6 races remained.

The god had watched it happen but gave their creations the benefit of a doubt, hoping they would learn their lesson and cease to fight on their own accord. But when the remaining sapients simply went to look for someone else to dominate after they had caused an entire species and an entire race to go extinct, the god had had enough.

The god wanted to punish the greedy and power hungry - as those types had led the fights against the extinct species and race - but spare the helpful and kind. Not everyone had participated in the slaughter, but few had tried to stop it. And rarely had an attempt ended well.

So, the god decided to create Dungeon Cores, giving them the mission of luring the greedy into their dangerous depths with promises of riches. Then the god gave sapients the ability to earn Skills, Achievements and Abilities. They could now earn experience by leveling up their Skills or - as an incentive to the violent and power hungry to enter Dungeons - killing creatures in Dungeons. When one had enough experience they would level up and gain two points to their 6 main Ability Scores.

Why 6? The god gave each of the 6 sapient species, which had turned against the 8th, a natural affinity with one of the main Ability Scores. They did the same to the 6 remaining races of the 7th sapient species.

The 7th Ability Score was then made to represent the fallen species and race and to help prevent their fate from befalling on another.

When the god created this system for the sapients, the creatures it had granted mana to, got access to it as well, but in a different form for each species. Some species could no longer truly die of old age, some granted massive strength or a special power. Several now earned experience simply for being alive while having mana flowing through their blood. But where sapients could gain many Skills over their lifespan, semi-sapients were instead born with one or more Skill, but few would ever get another Skill.

The god decided to keep this, despite it having been unintentional. As these species had gotten a part of the system designed for sapients, the god named them semi-sapients.

However, the god still wanted the world to have some magical creatures that couldn't level up, and so gave a smaller amount of mana, than the semi-sapients had gotten, to several species.

No other beings, than those that could level up, had any reason to enter a Dungeon, so the god made them unable to do so.

In the beginning, this system worked as intended. Greedy, violent and power hungry sapients entered a Dungeon and few of them came out alive.

But as the good, kind and helpful sapients had little reason to enter Dungeons, they rarely did. This meant that the sapients which exited a Dungeon, could much more easily dominate others with the new found power and riches the Dungeon Core had given it. Good sapients still got experience from leveling up their Skills, but rarely could they compare to a dedicated Dungeon visitor in a one on one fight. The good sapients tried to help others against these powerhouses, but found themselves outnumbered. After all, some power hungry sapients were cowards and had no problems gaining positions of power by supporting the powerful Dungeon visitors.

To fix this problem, the god created tier ups and Breakthrough Orbs. This way, all sapients had a reason to enter a Dungeon several times in their life, while still making it more likely for the greedy, violent and power hungry to want to dive too deep into a Dungeon and get killed as a result.

The god then reset everyone's levels to once again level the playing field and thought the problem was fixed. But the good, kind and helpful sought no power and thus few of them had reason to want to tier up at all. Leaving them powerless against any wandering Dungeon visitor.

To create more initiative, the god created Classes to come with a tier up and Skills to suit these Classes. Some Classes would be geared toward a peaceful lifestyle while others more suited for an adventurous one.

The change worked and good, kind and helpful sapients started gaining strength to defend themselves against the dwindling mass of greedy, violent and power hungry sapients.

With the change to the sapient system it changed for semi-sapients as a result. The semi-sapients adapted well to the tier up part of update but could not gain Classes due to not being sapient. The god decided to instead let semi-sapient gain a suitable Skill with their tier up, as they had less of those than sapients did.

At this point the god felt bad for all the creatures that weren't included in the system they had made. These creatures couldn't gain levels or Skill or Achievements or Abilities. The god wanted to include them in the system but didn't have enough power to include that many creatures in the system, as they had used their power for so many other things. Instead the god gave all species outside the system the 6 main Ability Scores as hidden Ability Scores and gave them a chance to sacrifice part of an Ability Score in exchange for an innate Skill. They still didn’t have levels nor did they get any Skills except for the innate ones.

While the world was not perfect, the god still loved it.

One such imperfect thing was the Dungeon Cores, for despite their mission to rid the world of evil they sought to kill all that entered their Dungeons, whether they be good or bad. The god tried to remedy this by giving Dungeon Cores their own system with Achievements and Abilities suited to them. They linked the tier up of Cores to the number of bad sapients they had killed, hoping this would make the Dungeon Cores start to focus on their mission.

But no Dungeon Core ever reacted to their new system.

Finally, the god realized what had gone wrong with the Dungeon Cores. They were not sapient or even semi-sapient and thus they had no thought, no concept of right or wrong or their mission in life.

Only instincts.

But now the god was mostly out of power and needed to rest to regain it.

And when gods need rest, it takes millenia for them to truly recover.

Besides, it was mostly the greedy, violent and power hungry sapients, who died in Dungeons anyway. Surely, the god could rest a while.

When resting the god didn’t truly sleep, but simply became less aware of what happened in their world.

And thus, less able to act on anything.

Though now lower in number, the greedy, violent and power hungry sapients never truly ceased to exist. They came up with new ways for getting their way and with the god now resting and thus less aware, they often got away with it too.

One thing the god did notice, was when the soul of a sapient fused with a brand new Dungeon Core. The god saw that it was good and gave the new Core what blessings the weakened, resting god could.