The following are terminologies found in the story.
Awakened - The phenomenon where humans awaken special powers.
Dungeon Break - A Gate undergoes full opening after 7 days, then a Dungeon Break occurs. The magic beasts that were normally confined to the inside of the Gate can now leave the Gate, causing destruction and mayhem outside.
Eternal Sleep - An illness that results from constant exposure to magic which causes the patient to sleep forever. Their life also waste away quicker thus life support devices are needed to keep them alive.
False Ranker - Hunters that have the ability to manipulate their magical points. They willingly choose to manipulate when being tested. That granting them the Title of False Ranker.
- Guilds - Official large-scale groups of hunters that raid Gates. Higher level guilds are considered to hold power rivaling countries. In return for purchasing the rights to gates from the Korean Hunters Guild Association, they are expected to answer calls from citizens when requested.
- Gates - Tunnels that connects the real world to dungeon, where the monsters resides. Gates are classified as Rank E, D, C, B, A, and S.
Hunters - Those possessing mysterious magical abilities. Even the weakest, E-Rank hunters, have slightly abnormal strength and regeneration compared to normal people.
- Magic Core - A size of a human fist, its black color was reminiscent of a black hole. The Core was something that came from A-rank Magic Beasts; the highest quality item that carried a price of 1 billion won.
- Magic Beasts - Hostile creatures found in Dungeons and Instant Dungeons.
- Mana Crystals - It was one of the treasures that could be found in Dungeons.
National Level Hunters - A title granted to a Hunter that possess the power of an entire country's military might and has cleared at least one S-Rank Dungeon. There are only 5 of them in the entire world.
- Red Gate - These are gates that connects two worlds which only appears in B-Rank gates above. Once manifested, it completely seals the gate off, preventing entrance or exit. The only way out is to kill the boss, the gate opens by itself, or all the hunters dies.
- Return Stone - Allows the owner to return to the nearest safe place.
- Rune Stone - A stone that contains skills usually dropped from high ranked magic beasts and hunters.
- Reawakened - Reawakened Hunters is a unique case as not all Hunters can be reawakened. A hunter's stats are set when they receive the "awakening" or "power". However, some hunters get awakened again after the first time. There have been cases of C-Ranks plowing directly to an A-Rank, or a B-Rank shooting straight to S-Rank.