The Team Rocket Hideout (Japanese: ロケット団アジトTeam Rocket Hideout), called Rocket Hideout in the Generation I and III games, and also known as Rocket HQ in the Generation ITown Map, is a four-floored underground complex beneath the Rocket Game Corner in Celadon City. It is a secret base built and used by Team Rocket to facilitate and administer their operations.
Access
The secret switch concealed behind a poster in the Game CornerLocation preview of Team Rocket Hideout in Generation III
The Rocket Hideout is accessed by pressing a switch behind a poster in the Rocket Game Corner in Celadon City. A Team Rocket Grunt is guarding the poster in question when the player first approaches it. After being defeated, the Grunt retreats into the base, leaving the poster unguarded, and enabling the player to approach. Once the player activates a switch behind the poster, the stairs to the hideout will appear. In Generation VII, the Grunt will only battle the player once Cubone has been kidnapped in Lavender Town.
In Generation II, the Rocket Hideout is referred to when the player walks and selects the poster at the back of the Rocket Game Corner in Celadon City. The words, "Hey! Under this poster... There's nothing!" will appear, a reference to the original access point.
Features
This is the first time that the player encounters spin tiles, a special type of tile that, when stepped on, will uncontrollably spin the player in the direction of the arrows until they hit a stop tile. These are used on the second and third basement floors to create a complex maze.
The Rocket Hideout briefly appeared at the beginning of File 3: Giovanni, where Red was seen freeing some imprisoned Pokémon in there, as well as encountering Giovanni for the first time.
The Rocket Hideout appeared in Tauros the Tyrant and The Jynx Jinx, where Red inflitrated it, disguised as a Team Rocket Grunt, in order to get information regarding Green's whereabouts. Like in the games, the entrance to the hideout could be opened by pressing a switch behind a poster in the Rocket Game Corner. In the hideout, Red found a laboratory, where Team Rocket was creating an artificial Pokémon from Mew's cells, intending it to be their ultimate weapon. However, they were lacking enough genetic material to complete their creation. Blaine was one of the scientists working on the project. After the Pokémon was completed later, it escaped, presumably destroying the hideout.
The Rocket Hideout appeared in PZ05. After being scared away by ghosts inside the Pokémon Tower, Satoshi followed a pair of Team Rocket Grunts leaving the tower into their hideout and snatched one of their Silph Scopes before leaving. His infiltration was observed by Giovanni through surveillance cameras, ordering his minions to leave him alone out of curiosity in the intruding child.
In the TCG
The following is a list of cards mentioning or featuring Team Rocket's Hideout in the Pokémon Trading Card Game.
Team Rocket's Hideout Cards listed with a blue background are only legal to use in the current Expanded format. Cards listed with a green background are legal to use in both the current Standard and Expanded formats.
If the player skips the Rocket Hideout using this method, it is still possible to enter this place at any point later and potentially break the normal gameplay sequence. For instance, once the player obtains the Earth Badge, Giovanni appears to disband the Team Rocket and permanently leave the current game as expected in normal gameplay. However, as long as the player has not obtained the Silph Scope, then Giovanni and the Team Rocket members still permanently remain in the Rocket Hideout as if the Team Rocket was never disbanded.
Team Rocket 
