HacX (pronounced "hacks") is a first person shooter game. It is a licensed total conversion for Doom II. It was created by Banjo Software in 1997, and featured an entirely new set of graphics. HacX uses a DeHackEd modified version of the Doom engine and the authors of HacX paid id Software $5000 for the rights to market HacX as a commercial add-on for Doom II.