A multi- player adapter (due to design sometimes referred to as a four- player adapter ) is an accessory for video game consoles, which allows the connection of more controllers than are provided on the base unit. A multi- player adapter often has one or two connections for the console and offers usually three to five ports for controllers.

Multiplayer adapter appeared inter alia, for consoles NES, SNES, Sega Mega Drive, Sega Saturn, Sony PlayStation, and their successors, as well as for home computers like the Commodore 64, Amiga and Atari ST.

Codemasters trod the J -Cart for the Mega Drive another way, the controller ports 3 and 4 are located directly on the game module. So you can play files without a multiplayer adapter. With the late launch and the renunciation of the back module for CD -ROM into the next generation of consoles as a storage medium, the J -Cart, however, was only a short-lived exotic car in the video game market.

With the advent of consoles like the Nintendo 64 and the Sega Dreamcast, which already offer four ports, and the increasing proliferation of online services specifically for these consoles, decreased the importance of multi-player adapter. With the introduction of wireless controllers as standard ( see Xbox 360, PlayStation 3, Wii ) the importance of multi-player adapters decreases even more.