Fissures
“Fissures appear in all sorts of forms, and monsters crawl out of the space that is opened up. After a while, it closes on its own like a scar.” (Ch. 5)
Temporary. Will close on its own.
Gates
“A gate, on the other hand, is a fissure that expands and evolves into the form of a door. Past the gates are dungeons, which are generally thought of as other dimensions.” (Ch. 5)
More stable than a fissure. Leads to dungeon.
Dungeons
“monsters come out gates through the dungeons as well, but a dungeon must be cleared within a certain amount of time. The condition is usually killing the boss monster.” (Ch. 5)
Must kill the boss monster inside within a certain period of time.
Open Dungeon
Gate is open. Allows people to enter and leave as they please.
Closed Dungeon
Gate is closed. Closes once there are enough people. Opens after condition (usually killing boss monster) is met.
Sunken Dungeon
Gate is closed. Sucks people into the dungeon. Opens after condition is met.
Special Dungeon
Gate opens for people that meet its requirements.
Great Dungeon
“But judging from that miniscule percentage, a Great Dungeon shouldn’t be that easy.” (Ch. 55)
A dungeon harder than other dungeons. Capable of destroying an entire world.
Dungeon’s Clock
“When a Dungeon’s Clock first appears, the band is full of a specially colored mana. As time passes, the mana slowly disappears… If the dungeon is not fully taken care of by the time the mana in the clock runs out, the dungeon explodes.” (Ch. 20)
Appears around the gate. Mana fills up when raid begins before starting to disappear after a certain period of time. Raid must be finished before Dungeon’s Clock runs out. If not, it leads to erosion.
Erosion
“Once the dungeon explodes, all of the monsters and items inside the dungeon spill out, and the surrounding area changes into that of the dungeon. In other words, the area becomes a wasteland unsuitable for normal humans to live in.” (Ch. 20)
If the Dungeon’s Clock runs out of mana, it explodes and turns the surrounding area into a wasteland.
The Blue Ark
A last emergency system when Earth is overrun by dungeons. The administrator can activate it once 80% of Earth has been invaded. The Blue Ark will become a dungeon and invade other worlds to find new land. Passengers will include all living beings. (Ch. 100)
Roles
Administrator
“The administrator is the one who encourages awakened ones, manages Earth’s system, and stands in the front lines to attack and defend in response to invasions.” (Ch. 100)
Special existence selected by the system to protect the world from invasions. Once world becomes a dungeon, the Administrator becomes the final boss monster.
Guardian
“People who use this orb become this star’s Guardian and gain great power. Only if they have the will to protect this star will the orb’s power be maintained. If this world ends, they take on the role of supporting the Administrator.” (Ch. 105)
The Administrator will choose Guardians by giving them one of five orbs. Once world becomes a dungeon, the Guardians become mid-level boss monsters.