What Is a Game ROM? Complete Guide to ROM Files, Emulation & Legality

A game ROM (Read-Only Memory image) is a digital file containing the complete data of a video game cartridge, disc, or arcade PCB.

What's Inside

• Program code (CPU instructions)
• Graphics (tiles, sprites, textures, palettes)
• Audio (samples, sequences, driver code)
• Level data, scripts, tables

Common Extensions

• .nes, .sfc/.smc, .gba, .n64, .z64, .gbc, .gb, .md/.gen, .iso/.bin/.cue (disc), .chd (MAME compressed)

How It's Used

1. Dumping: Hardware (Retrode, Kazzo, custom PCB) reads original media → file
2. Emulation: Emulator (software recreating console hardware) loads ROM → executes
3. Flashcarts / ODEs: EverDrive, FXPAK Pro, MODE, GDEMU play ROMs on real hardware

Legal Status

• Creating your own dump from owned media: Legal in many jurisdictions (fair use / private copy)
• Downloading ROMs you don't own: Copyright infringement (piracy)
• Distributing: Illegal worldwide

Preservation

Projects like No-Intro, Redump, MAME verify checksums (SHA-1, CRC32) to document authentic, unmodified ROMs for historical preservation.