Difficulty Level/Rating

“How strong is that Jaldabaoth you mentioned? I don’t remember hearing or reading about him. It would help us if you could tell us his difficulty level.”
Lakyus stepped forward with a stern expression on her face.
“My colleague Evileye is the one who is most familiar with Jaldabaoth’s strength, but we do not know the specifics yet. We will update you later.”
Adventurers rated the strength of the monsters which they encountered by their difficulty ranking. The higher the number, the stronger the opponent.
However, it was an unspoken rule that one should not rely too heavily on difficulty rankings, because it would lead to nasty surprises. The strength of monsters varied even within their own species and at best, a difficulty ranking was an educated guess. Thus, it was not a value that was frequently used.
However, it was a simple way to explain things to a group like this.

- Overlord; Vol 6; Chapter 10

“Difficulty... yeah, speaking of which, what rank were Jaldabaoth and the insect maid?”
Lakyus was lost as to how she should answer. If she was honest, it would most likely shatter their resolve, but if they went into battle with a false impression of the enemy because she lied to them, it would be just as disastrous. She agonized about it for a while before deciding to tell the truth.
“...150.”
“Aye?”
Everyone who heard Lakyus’ voice had the same reaction.
“The insect maid’s difficulty ranking was at least 150. Jaldabaoth himself is estimated at 200 or more.”
“Hah?!”
Everyone aside from Lakyus was speechless. That much was expected. Even the highest-ranking orichalcum adventurers would only rate around 80 on the difficulty rankings. Although one could still triumph over a foe ranked roughly 15 points over oneself, trying to do the same with an enemy ranked almost twice as high as oneself was nothing short of laughable. And then—
“Wait a minute! Are you saying Momon-san is going to fight that difficulty 200 monster by himself?”
“Exactly. That’s why I said we’d just be getting in the way.”
“But that’s not the same... you said 200? Are you kidding me? Are all adamantite-ranked adventurers that strong?”
“If only. Even we’re ranked around 90 at best.”

[...]

Lakyus had not lied, but neither had she told them the whole truth. Although Lakyus herself was rated at 90, Evileye was over 150, which was how she had come to the conclusion about the insect maid and Jaldabaoth. And that was also why Evileye was not part of this defensive line.

- Overlord; Vol 6; Chapter 11