ROM cartridge

A ROM cartridge, also simply referred to as a cartridge or cart, is the storage device in which many of the Pokémon games have been contained.

Throughout the Pokémon game series, all of the core series games have been stored on ROM cartridges, with many variances between them. Many side games have also been on cartridge but some have been for the GameCube and Wii (on discs, not cartridges). The ROM cartridges for the Game Boy, Game Boy Color, Game Boy Advance, and Nintendo 64 are officially called Game Paks, while Nintendo DS, Nintendo 3DS, and Nintendo Switch ROM cartridges are officially called Game Cards.

Specifications

Game Boy: 2.125 × 2.5 inches.
Game Boy Color: 2.125 × 2.5 inches.
Game Boy Advance: 2.125 × 1.375 inches.
Nintendo DS: 1.25 × 1.375 inches.
Nintendo 3DS: 1.25 × 1.375 inches. (Not counting anti-DS knob on side)
Nintendo Switch: 1.25 × 0.8125 inches.
Nintendo 64: 4.5 × 3 inches. (Measured from top of arch)

Core series

All core series games are contained on cartridges.

Generation I

All Generation I core series games were released on Game Boy cartridges. The Western version of Pokémon Yellow was released on a Game Boy cartridge, but is enhanced when played on a Game Boy Color.

Generation II

Pokémon Gold and Silver were released on Game Boy cartridges, but are enhanced when played on a Game Boy Color; they were marketed as Game Boy Color games that are backwards compatible with the Game Boy.

Pokémon Crystal was released on a Game Boy Color cartridge.

Generation III

All Generation III core series games were released on Game Boy Advance cartridges.

Generation IV

All Generation IV core series games were released on Nintendo DS cartridges.

Pokémon Diamond, Pearl, and Platinum were released on the dark gray-colored NTR-005 cartridges. Pokémon HeartGold and SoulSilver were released on the black-colored NTR-031 DS cartridges, which are for games that use Infrared connections, such as connecting to the Pokéwalker.

Generation V

All Generation V core series games were released on Nintendo DS cartridges, specifically the black-colored NTR-031 DS cartridges, due to being able to connect to each other through infrared. These games are also DSi-enhanced, bearing special DSi exclusive features such as video chat and region locking. Such features are also compatible on the Nintendo 3DS. Because of these features, these games all have a serial number that starts with TWL instead of NTR.