Although video game console emulators themselves are legal, the software that is used with the emulators is illegally copied. Emulators promote piracy by allowing illegally copied software, such as games, to be played on them, according to Nintendo.
Video game console emulators allow computers, and sometimes even other gaming consoles, to imitate the hardware and behavior of a specific console. This allows the new platform, such as a computer, to play downloaded games, called ROMs. Since the copyrights and trademarks of games are corporate property, ROMs themselves are illegal, according to Nintendo. However, ROMs that are created by private individuals and are part of the public domain are considered legal, as long as the information is authentic and has not been copied from another source.