Terrain is the term used for what the Pokémon in a Dungeon. There are 5 types of terrains possible in a dungeon, however, Water, Lava, and Valleys can't appear in the same dungeon.
Ground
This is a terrain that always exists in a dungeon, as it is the solid matter all Pokémon walk on in a dungeon. They appear in lots of variations, from desert sand, to undeep water.
Walls
Walls divide the floor into rooms and corridors, affecting the range of moves like Discharge, Growl, or Heat Wave. In rooms, the latter affect all enemies in the room, in a corridor their range is only 2 tiles around the user.
Note: Moves like Earthquake still affect team members in corridors, even if the user has the Nontraitor IQ Skill.
Water
This is the most common terrain found except for the ground or walls. Water Pokémon, Mobile Pokémon (like most Ghost-Types Pokémon), and Pokémon whose appearance on the screen always flies (examples: Gliscor can fly over water, but Fearow can't), can move over water like it is over ground. Any item thrown into it will stay in the water until a Pokémon picks it up by walking on the spot where it is.
Lava
Similar to water, lava is a terrain which appears most frequently in fire-based dungeons, like Mt. Blaze, Giant Volcano, or Inferno Cave. Fire-Type Pokémon, Mobile Pokémon (like most Ghost-Types), and Pokémon whose appearance on the screen always flies (Examples: Gliscor can fly over lava, but Fearow can't), can move over lava, however, non-Fire-Type Pokémon will get a Burned Status once they move over the lava. If healed while walking on the lava, putting another step on lava will still cause a Burned Status. Any item thrown into it will burn away and is lost.
Valleys
Valleys don't appear in many dungeons. They're empty crags that appear in different kinds, like dark holes (like in the Chasm Cave in the future of Sky, Darkness, and Time) or clouded areas (like in Sky Tower in Red and Blue, and it's PMD2 counterpart Sky Stairway). Only Mobile Pokémon (like most Ghost-Types), and Pokémon whose appearance on the screen always flies (Examples: Gliscor can fly over valleys, but Fearow can't) can move over these areas. Any items falling on these areas will immediately fall too far to get back and are lost forever.
Mobile Pokémon
Mobile Pokémon can move through walls. There are several ways for Pokémon that normally can only over ground to extend their movement:
- Using a Mobile Scarf: a Pokémon holding a Mobile Scarf becomes Mobile, becoming able to move over every terrain there is. However, being Mobile costs a Team Leader 5 Belly per step.
- The All-Terrain Hiker IQ Skill: allows a Pokémon having the IQ Skill on to move over water, lava, and valleys. Non-Fire-Type Pokémon moving over lava will still be afflicted by the Burned Status. This IQ Skill can only be learned by Pokémon in IQ Group C.
Pokémon that move onto terrain they can't access without the latter will be warped away once the source of this ability is removed. For example, if the Mobile Scarf held by the temporary-mobile Pokémon is removed, the Pokémon will lose its mobile abilities and will immediately be warped if it's on a terrain that it can't access without help.