If you don't want to risk legal issues, consider these options:
If you have acquired a legal Neo Geo ROM pack (for example, by dumping your own cartridges), here is the standard workflow:
To use a ROM pack, you need an emulator compatible with your device. roms neo geo pack
Crucial Note on BIOS: Most emulators will not run Neo Geo games without the neogeo.zip BIOS file placed in the correct folder. This file dictates the region of the system (Japan, USA, Europe) and enables features like the crosshairs in shooting games or the "CDZ" BIOS interface.
The Neo Geo boasts a "no filler" library. Because the cartridges originally cost over $200 each (and arcade boards even more), developers only released high-quality titles. A single Neo Geo pack gives you access to: If you don't want to risk legal issues,
It is impossible to discuss ROM packs without addressing the legality.
Technically, downloading ROMs for games you do not own constitutes copyright infringement. The copyright for Neo Geo games is currently held by SNK Corporation (now owned by the Saudi Arabian Electronic Gaming Development Company). Crucial Note on BIOS: Most emulators will not
However, the scene is complicated by the concept of Abandonware. While SNK is active, releasing new games (like King of Fighters XV), they have historically shown a degree of leniency toward the emulation of their 30-year-old back catalog, often focusing legal efforts on sites profiting directly from piracy rather than individual preservationists.
The "correct" legal way to build a ROM pack is to "dump" the games yourself—connecting an original Neo Geo cartridge to a specialized device to read the data and create your own ROM files.