Game Genie – Peripherals

The Game Genie was a pass-through cartridge cheat device that allowed players to enter codes modifying game values in real time, enabling infinite lives, invincibility, and other modifications in thousands of games without any ROM modification.

The Game Genie was invented by Codemasters in the UK and licensed to Toy company Galoob for North American distribution. The device worked as a cartridge pass-through: the game cartridge inserted into the Game Genie, which inserted into the console. Before the game launched, players entered alphanumeric codes — typically six or eight characters — which the Game Genie used to intercept specific memory addresses and substitute different values when those addresses were read by the CPU. The technique required no permanent modification to the game cartridge or console hardware, and codes could be entered fresh each session. A code booklet included with the device covered hundreds of games, and Galoob maintained a telephone hotline where players could call for additional codes. Nintendo sued Galoob in 1990, arguing that the Game Genie created unauthorised derivative works of Nintendo's software. The lawsuit was notable and influential: federal judge Fern Smith ruled in Galoob's favour in 1991, finding that the Game Genie did not produce a fixed copy of any game and that its modifications fell within fair use as transformative personal use. The ruling was significant for establishing that hardware-level game modification did not constitute copyright infringement, a legal principle that has implications extending well beyond cheat devices. Nintendo appealed but settled in 1992, reportedly paying Galoob $15 million in exchange for a licence.

Key Facts:

Nintendo sued Galoob in 1990; a federal judge ruled in Galoob's favour in 1991, establishing an important fair use precedent
Operated by intercepting specific memory address reads and substituting different values without modifying any hardware
Galoob maintained a telephone hotline providing codes for games not covered in the included booklet
Versions were produced for NES, SNES, Genesis, and Game Boy, each physically different to fit the respective cartridge port

Verdict: The Game Genie was a commercial success that sold millions of units across multiple platforms, and its legal victory against Nintendo established a meaningful fair use precedent for game modification that continues to be cited.