In the Pokémon world, there are many different dimensions and alternate realities. While trivial references to other dimensions were made early in the franchise's history, the concept was truly introduced and explored in Generation IV with Pokémon Diamond, Pearl, and Platinum.
- Main article: Unown Dimension
While researching ruins with depictions of the Unown, Spencer Hale was transported into this dimension. His daughter, Molly, inherited a puzzle box found there that gave her contact with the Unown, which granted her wishes. Such was the strength of the world she created, that an opening to the dimension appeared in the entrance hall of her mansion. During this time, the Unown gained powerful control over Greenfield, but all contact with the dimension ended after Molly wished for things to go back to the way they had been before. A portal to the dimension was opened above Mt. Silver some time later, and an Unown fell out, but it had no trouble returning when it was in good health. The Unown Dimension also became the battleground of Dialga and Palkia, before their battle moved to Alamos Town.
Travel between the Unown Dimension and the real Pokémon world has been shown to be possible through a puzzle box and a portal. The direct connection between ancient sites like the Ruins of Alph and Solaceon Ruins and their large concentrations of Unown remains a curiosity amongst Scientists.
- Main article: Ghost World
In the anime an entrance to it appeared in Ghoul Daze!, where the Pokémon Summer Academy staff accidentally opened a portal to it when renovating the Summit Ruins. A ghost girl and Dusknoir were both let out, with the Dusknoir trying to take the ghost girl back to the Ghost World, while she was trying to abduct people and take them to the Ghost World. Another entrance appeared in Scare at the Litwick Mansion!, where the Litwick in Litwick Mansion tried to lead Ash and his friends there while draining their life energy.
A device called the Time-Space Axis in Michina Town is able to indicate the condition of every minute change in the time-space continuum, serving to mirror the movements of the timespace dimensions and thus monitoring the likelihood of potential cataclysm.
- Main article: Distortion World
The Distortion World is first accessed when the player reaches the summit of Mt. Coronet, the Spear Pillar, to stop Team Galactic's plot to control Dialga and Palkia. When the Lake guardians are unable to control both Dialga and Palkia, Giratina comes and swoops on Cyrus to stop him from destroying the world. After Cyrus is taken away by Giratina, the player must follow him, and with the help of the lake guardians and Cynthia, navigate the area. The Distortion World is said to be another universe or world parallel to the Pokémon world. Two known gateways to it exist: one at the top of Mt. Coronet on the Spear Pillar, and another in Turnback Cave. It is a dark place with floor-like sections floating at many different angles. The world disobeys the normal laws of physics, allowing the player to walk and surf on walls in any direction. The only Pokémon known to inhabit the Distortion World is Giratina.
In the anime, it has a counterpart known as the Reverse World.
It and the Spatial World are usually far away from each other, but due to shock waves caused by Arceus awakening from its deep slumber, they clashed. This resulted in a battle between Dialga and Palkia, because each Pokémon thought that the other was trespassing onto its territory. It subsided a short time before Arceus woke up.
In Diamond and Platinum, Cyrus summons Dialga from there. In Platinum, when the player battles Dialga after entering the Hall of Fame, it comes through a dimensional rift created by Cyrus's original summoning of it. In Pokémon Omega Ruby and Alpha Sapphire, Dialga can be caught because of a dimensional rift while soaring in the sky.
It and the Temporal World are usually far away from each other, but due to shock waves caused by Arceus awakening from its deep slumber, they clashed. This resulted in a battle between Dialga and Palkia, because each Pokémon thought that the other was trespassing onto its territory. It subsided a short time before Arceus woke up.
In Pearl and Platinum, Cyrus summons Palkia from there. In Platinum, when the player battles Palkia after entering the Hall of Fame, it comes through a dimensional rift created by Cyrus's original summoning of it. In Pokémon Omega Ruby and Alpha Sapphire, Palkia can be caught because of a dimensional rift while soaring in the sky.
- Main article: Lake guardians
- Main article: Interdream Zone
The Interdream Zone is located between dreams and reality and is investigated by Professor Burnet in the spin-off game Pokémon Dream Radar. The Interdream Zone is mentioned again in Pokémon Sun and Moon by Scientists at the Dimensional Research Lab in Heahea City, which is led by Professor Burnet.
- Main article: Ultra Space
Ultra Space is an alternate dimension that is home to the Ultra Beasts. Pokémon Sun and Moon, and later Pokémon Ultra Sun and Ultra Moon, introduced the concept. Unstable portals called Ultra Wormholes connect the Pokémon world and the various worlds that are connected to Ultra Space.
Pokédex entries that reference dimensions
- This troublemaker sends anything and everything to faraway places using its loop, which can warp space.
- Ash and his friends were transported into the Togepi Paradise, a dimension connected by several gateways throughout the Mirage Kingdom, in A Togepi Mirage!.
- Deoxys's unnamed world appeared in Pokémon Ranger - Deoxys' Crisis! Part 1 and Part 2.
- Ash and his friends visited the Mirror World, an alternate dimension with strong connections to the Reflection Cave, in The Cave of Mirrors!.