PNACH is a file format used by PlayStation2 console emulating software. PNACH contains data in text format, which can be edited using and text editor. The file allows users to apply patches to games, for example by using codes that were distributed once by GameShark in the form of special cartridge devices.

PNACH files allow users to ‘cheat’ game source code and modify it in order to gain some advantage for the player, usually in the form of inifinite lives or level skip option.