The DUC file type is primarily associated with 'Action Replay' by Datel Ltd.. Action Replay is the brand name of a series of devices created by Datel, primarily used for changing the behavior of video games. Currently, Action Replay is available for the Nintendo GameCube, Game Boy Advance, PlayStation 2, Xbox, Nintendo DS, and PlayStation Portable (PSP). Codejunkies sells the Action Replay hardware. Shuny's Savegames Converter will convert the files to other, perhaps more useful, formats. The DUC file is a newer format; older will have the extension DSS.