Chapter 1. Some brushing on the text, removed mention to 'coin' as I decided that Essence would be the world's currency, and added descriptions for the main characters. Most important I think is the mention that Glom beastfolk race was derived from gerboas and not rats.

Chapter 1:

"Nero!" His mom shouted from downstairs. "I hope your hair is groomed, it is time for your coming-of-age ceremony!"

The Hairless ape beast-kin of the Minnid tribe looked at himself in the mirror for the umpteenth time. Differently from the other beast-kin races, there was no tail at the end of his spine. He had somewhat long head fur, the only spot where it grew on him so far. He would grow some hairs on his arms, legs, chest and face when he grew older, but that wouldn't be a thick fur coating like the other beast-kin and it was still a few years ahead. His hair was slick, [...]

"Altia! Hi!," Nero greeted his friend. "Excited?"

Altia was the perfect girl next door. She had light brown hair, tied in a single braid that reached the small of her back, light brown eyes and a lighter complexion. She was pretty but not overly gorgeous, smart, easygoing, and focused on her studies. She knew what she wanted to be [...]

[...]

Standing on a raised dais, the village's assigned squiig [Gadgeteer], Glom was waiting next to an open crate.

The squiig was a race of diminutive beast-folk less than two feet tall with their roots on skipping prairie rodents, the gerboa. He had a long and thin tail that ended with a tuft of fluffy black fur that resembled a painter's brush, digitigrade and long legs that he used to hop, skip, and jump fast and far, oval ears decorating the top of his head and a rodent's snout with long whiskers. The squiig had prominent front teeth but these didn't grow like their animal counterparts.

"Line up, I said!" The diminutive [Gadgeteer]'s sharp voice [...]

On chapter 2, I removed the mention of temporary Skills and the limit of using Essence from low-leveled monsters. The exponential requirements would make these useless already. I also added explanation about level, tier, rank, and grade.

Chapter 2:

"No need to get angry, sir," The diminutive scientist replied. "All the new adventurers are level zero, their first delve is tomorrow. I'd suggest to let him do his first delve, then we can convey at my workshop after dusk where I'll make a more detailed analysis."

Every new adventurer would earn their first level and their fist Attribute Point after they killed a few monsters in the Dungeon. From then on, they'd have to use essences to level up, the amount of essence energy required increasing exponentially as they leveled. To make matters more complicated, the energy of the Essence crystal every monster dropped increased linearly with Level, then multiplied by a factor involving the Level of the adventurer as compared to the Level of the monster.

And as the straw that broke the camel's back, several adventurers would find stagnation at some point well before their level cap, hitting a sweet spot where the monsters they can hunt with low risk are profitable enough to guarantee a livelihood but not strong enough to allow them to advance in a reasonable timeframe. It all depended on their life choices like the Class and Skills they picked along the way.

These choices were permanent. One had only so many slots for Class and Skills and once those were filled, they would stay for good.

It happened to Nero's father of all people. He was way over Level 150 with a Class belonging to the fourth tier and nothing below level 120 would allow him to advance. He'd need to hunt tens of thousands of monsters at that level. And now that he had a family to provide for, he couldn't risk going after stronger monsters. His parents retired and were living off of a nest egg built over three decades.

While the adults argued, Nero looked at a chart drawn on a banner hung next to the dais with information for the novices. He knew all that by heart, but it didn't hurt to refresh his mind.

Levels, Tier, Rank, Grades. These were the four main concepts that governed an Adventurer's life.

Levels were straightforward. Every creature that could manipulate Essence, a mysterious force found in crystals monsters left behind upon their deaths, had a level. Nero now had one, apparently stuck at zero.

Tiers referred to the several Classes a person would acquire along the way. The first tier was called "novice" and allowed them to have a base Class. Then at every fiftieth level, one would reach the "next tier" and gain the ability to get an advanced class. This pattern would repeat until one hit their level cap. Nero's parents would never reach the fifth-tier.

Ranks were how they classified the Dungeon. Every rank was equivalent to roughly five levels. The Dungeon next to the village of Hom was called "The Goblin's Den" and was rank-I. it meant the monsters inside were on the range of one through five, with some outliers a bit higher. Adventurers that entered Dungeons above their own level divided by five usually didn't come back.

Finally, there were grades. Grades referred to the quality and rarity of equipment and cards. Higher grades would grant more powerful effects but were also harder to come by. The lowest grade was gray, then white, green, blue, yellow, purple, and finally the very desirable orange. In some other places, they called these grades trash, common, uncommon, rare, ultra-rare, epic, and legendary, but around where Nero lived they just used the colors.

"The day after tomorrow," Byron huffed, pushing the meeting to the next morning. "We will be at your workshop at the cry of the rooster, Glom."

Chapter 3. Brushing up the rules of engagement regarding Dungeons. Moved the party invitation to before they entered the portal. There is no "party invitation". Every Adventurer nearby is considered to be in the same "party" as they would absorb Essence from the kills and gain Accolades anyway.

Chapter 3:

Nero stood in line to enter the Dungeon. Despite the danger of an Overflow, an event where monsters poured out of a Dungeon in great numbers, spreading devastation for miles around its entrance portal, most settlements were built close to a Dungeon for two reasons. First, they were a source of the precious Essence and cards, and second, Dungeons needed constant cleaning by Delvers to avoid Overflow. As a Dungeon Overflowed, its rating would increase and the next Overflow would be even worse. Eventually, deadlands would form, a place where nothing except monsters thrived. Even the vegetation would be replaced by monstrous lookalikes.

It also meant that the Minnid Tribe's Dungeon would never be anything but a rank I Dungeon. They couldn't let it rest until it caused an Overflow or the village would risk its existence and the Dungeon would never grow. Similar to the ranked pink card resting on Nero's bandolier, a rank I Dungeon allowed adventurers up to level ten to enter. Anyone above that level would find that the portal would just refuse if they tried to enter and even if they forced, they would quickly die inside. Nero didn't understand why but it did.

"Nervous?" Altia teased, startling Nero.

"No," He grinned, pushing away the gloom mood at home. "I was born for this."

She laughed at his boast. Being the child of two adventurers of no small power, Nero was indeed born for this. Altia brushed her shoulder against his arm but shied away when he noticed. Nero wanted to invite Altia to delve with him. While large parties were shunned upon, delving in groups of two or three had inherent advantages from the added safety. He was afraid she would reject him.

"Should we party up?" She asked, drawing a big smile from him.

"Sure!" He replied, happy that she invited him.