A proper full set includes every BIOS. It also, in its complete form, includes CHD files (Compressed Hunks of Data)—the hard drive or CD-ROM images for newer arcade games like Killer Instinct or Dance Dance Revolution .
: MAME is unique because its ROM files are tied to specific emulator versions. Each update (released monthly) may change how a game is read. Having a full set makes it easier to use tools like clrmamepro to verify and update your entire library at once. Dependency Management mame full set roms better
MAME emulators are specifically tied to particular ROM set versions: A proper full set includes every BIOS