Gaia Memories

A Gaia Memory (ガイアメモリ, Gaia Memori?) is a mysterious device resembling a USB flash drive that contains all of the Earth's knowledge of what it represents. This enables its user to become a Dopant, or in some special cases a Kamen Rider. Every Gaia Memory is adorned with the first letter of its name, stylized to reflect the powers it imbues on its user. For example, the Injury Memory (acquired by Shotaro and Philip before the series begins) resembles a broken bone in the shape of the letter I. In order to transform into a Dopant, the Gaia Memory is first inserted into a device called the L.C.O.G (Living Connector Setting Operation Gun), also called a Connect Shooter (コネクトシューター, Konekuto Shūtā?), which then produces a USB port-like tattoo on the user's skin called a Living Connector (生体コネクタ, Seitai Konekuta?). Whenever the Gaia Memory is pressed onto the Living Connector, it enters the user's body and transforms the user into a Dopant.

This direct insertion will eventually drive its user insane from its addictive influence, which is why special belts called Memory Drivers (メモリドライバー, Memori Doraibā?) have been developed for use by high ranking members of the Museum to filter out these and other side effects. This weakens the Dopant visibly; high-ranking Museum members use some of the strongest Gaia Memories to more than compensate for this weakening.

Kamen Riders utilize Gaia Memories that have been refined such that they can only be used in specialized Memory Driver belts. These kinds of Gaia Memories were created by Shroud during her time as Fumine Sonozaki. This refinement makes them resemble USB drives, rather than the ribcage design on Dopant Gaia Memories, but further weakens the power of the Memories, only allowing access to the Memory's full power during a Maximum Drive.

To defeat a Dopant, a Kamen Rider has to use one of its Maximum Drive finishing attacks to eject and destroy the Gaia Memory, resulting in what is called a Memory Break (メモリブレイク, Memori Bureiku?). Evolved Gaia Memories require a direct strike on its location within the Dopant's body to execute the Memory Break. If the Dopant does not have a Living Connector, a Memory Break will not occur, however the Gaia Memory will still be ejected from the user's body. Dopants who use Memory Drivers are not susceptible to Memory Breaks.

T2 Gaia Memories
T2 Gaia Memories are next-generation Gaia Memories developed independently by Foundation X and were started by Shroud's research before she left the Museum. They are carried at all times by Jun Kazu. Sometime later they are found by the terrorist organization, NEVER. All of them are similar in appearance to the Gaia Memories used by Kamen Riders but can used to change into a Dopant or with a Memory Driver to become Kamen Riders.

Double Memories

 * Cyclone
 * Joker
 * Heat
 * Metal
 * Luna
 * Trigger
 * Fang (sentient memory)
 * Xtreme (sentient memory)
 * Prism
 * Stag (pseudo memory)
 * Spider (pseudo memory)
 * Bat (pseudo memory)
 * Frog (pseudo memory)
 * Denden (pseudo memory)

Accel Memories

 * Accel
 * Cyclone (Lend by Phillip)
 * Engine (sub memory)
 * Trial
 * Beetle (pseudo memory)

Skull Memories

 * Skull

Joker Memories

 * T2 Joker
 * Joker

Eternal Memories

 * Eternal
 * T2 Eternal

Executive Gaia Memories

 * Terror
 * Taboo
 * Clay Doll
 * Nasca
 * Smilodon
 * Weather (Almost treated as one)
 * Utopia (Given to Foundation X as a test sample)

Museum staff

 * Anomalocaris
 * Hopper
 * Sweets
 * Masquerade
 * Bat (Message to Double)

Gaia Memories sold to Black Market

 * Injury (Acquired before event of the series)
 * Magma
 * T-Rex
 * Money
 * Cockroach
 * Sweets
 * Virus
 * Violence
 * Arms
 * Bird
 * Ice Age
 * Triceratops
 * Liar
 * Puppeteer
 * Nightmare
 * Beast
 * Zone
 * Yesterday
 * Gene
 * Jewel
 * Old
 * Ocean (found by Yui Aoyama)
 * Spider (Message to Double)
 * Bat (Message to Double)
 * Commander (W Returns: Accel)
 * Unicorn (W Returns: Accel)
 * Eyes (W Returns: Eternal)

Gaia Memories experimented by Isaka Shinkuro

 * Invisible
 * Quetzalcoatlus

Kamen Rider × Kamen Rider Double & Decade: Movie War 2010

 * Dummy
 * Shinigami Hakase

Kamen Rider Double Forever: A to Z/The Gaia Memories of Fate
T2 Gaia Memories can be used by any Rider who uses GaiaMemory, although that wasn't shown with any other Memories except Eternal and Joker. They are capable of selecting their users who have a high compatibility to them as if destined by fate.
 * T2 Accel
 * T2 Bird
 * T2 Cyclone
 * T2 Dummy
 * T2 Eternal
 * T2 Fang
 * T2 Gene
 * T2 Heat
 * T2 IceAge
 * T2 Joker
 * T2 Key
 * T2 Luna
 * T2 Metal
 * T2 Nasca
 * T2 Ocean
 * T2 Puppeteer
 * T2 Queen
 * T2 Rocket
 * T2 Skull
 * T2 Trigger
 * T2 Unicorn
 * T2 Violence
 * T2 Weather
 * T2 Xtreme
 * T2 Yesterday
 * T2 Zone

Special Edition Gaia Memories
In real life there exist exclusive illustration or toy Gaia Memories that do not exist in the television series, usually released in Kamen Rider related media, such as Televi-kun and Ganbaride.
 * Kamen Rider Ryuki
 * Kamen Rider Hibiki
 * Ganbaride
 * Televikun (Note: this toy gives off the call of the Joker and Cyclone Memories, Double's catchphrase, and the "Televikun Maximum Drive")