Dungeons and Adventurers.

Elier, this planet had a certain system to it, unlike the way other planets worked, where people earned money from either working for other people or creating valued papers for themselves. This world revolves around gaining a certain currency called E(Eliets), this worked as a currency for the planet Elier. This was a currency that could only be gained by slaying monsters in dungeons and trading their drop, loot whatever you want to call them for E in the dungeon centers.

In this world however, there lies a system on the levels or ranks in each and every adventurer explorer. The levels are unlimited but there were only 10 ranks in each level. G,F,E,D,C,B,A,S,SS,SSS. This ranks serve as a division in the different skills attributes you can attain. One must reach a certain threshold in their total attribute points to level up. G being 0 to 100, F 100 to 200. Till 1000 where the SSS is finally obtained. 1000 isn't the skill gap however, it can keep increasing. It's limitless. But not many attain the SSS.