Zero Isle East is part of the challenging Zero Isle dungeons. Upon entering, all team members are temporarily reduced to Level 1. Any extra stats and IQ gained from Gummis, drinks, or the like, are removed. The Pokémon will have all the moves it would have at Level 1, with any TM, HM or Egg moves being lost. No Pokémon found in this dungeon can be recruited. Additionally, the player is allowed to bring only 16 items at the start of the dungeon (though the player is allowed to collect more within the dungeon itself); any further items have to be deposited into Kangaskhan Storage before entering, or will be lost forever. Upon exiting the dungeon, the team members' IQ, stats and movesets return to what they were before entering the dungeon, with items obtained within the dungeon preserved as per usual rules.
The enemy Pokémon will gradually gain levels, although nowhere as fast as in Zero Isle North. Adding to the player's disadvantage is that opposing Pokémon possess IQ points: 150 at floors 1 through 15, 330 at floors 16 through 29 and 331 at floors 30 through 39 (causing them to not use their regular attack on these 10 floors). The amount of starting enemies is 2-3 on first five floors and 3-5 on later floors. Unlike every other Zero Isle, this dungeon does not have any naturally occurring Monster Houses and also has Hidden Stairs.
There's 4-7 items found on the ground, as well as 2-5 items buried in the walls (although the buried items are all money). However, items spawn sticky 5% of the time.
Floors 1 through 13 are medium-sized with 3-9 rooms. Floors 20 through 39 are large-sized, with the maximum amount of rooms changing back and forth in range from 10 to 14.
Jobs in this dungeon are ranked E or ★1 through ★6 by default, depending on the floor. There is light darkness present in the dungeon. There is water on floors 3, 5, 7, 11, 12, 15, 19, 22, 24, 26, 30, 31, 34 and 38. The IQ Booster activates every floor, though it will prove of little use in this dungeon. The turn limit is 2000, twice as long.
There is following weather occurring in the dungeon:
Cloudy at floors 4 and 5
Random at floors 10, 17, 26, 28 and 36
Fog at floors 12 and 20
As it is a Zero Isle dungeon, its difficulty is paired with many rare items such as Life Seed or Zinc spawning directly on the ground, as well as X-Ray Specs in the Kecleon Shop. In Explorers of Sky, the player can instead try their luck with Grab Bag if they manage to find the Secret Bazaar, as it also can contain rare items.
In Explorers of Darkness only, the player can also find type Gummis lying on the ground. On floor 20 only, the player cannot find throwing or edible items unlike in the rest of the dungeon, but only in Explorers of Time and Explorers of Sky.
There are locked chambers requiring Keys on floors:
At the end of the dungeon, the player can pick up White Silk and a Deluxe Box containing either Joy Seed or Life Seed.
Pokémon encountered
Each time player enters floors 35 through 38, only 14 of the following species that can be found on the given floor will be chosen. The unpicked Pokémon's spawn rate will be added to whichever picked Pokémon is next in the National Dex order, going back to the beginning if needed.
