Heretic is a fantasy first-person shooter that uses a modified version of the Doom engine. It was developed by Raven Software and published by id Software for PC MS-DOS in 1994. John Romero acted as producer on the game (and on the sequel, Hexen).

The premise of the game is basically the same as Doom: blast monsters, survive the many hazards and traps, and find keys or switches to open doors and escape to the next level. The main difference of course is that Heretic features wands, crossbows, magic, and a variety of fantasy-themed power ups and weapons. Heretic also has an inventory system which allows you to carry a certain number of items and select and use them when necessary.

The original version of Heretic was only available as shareware and contained three episodes. The retail version, Heretic: Shadow of the Serpent Riders, was distributed by GT Interactive in 1996, and featured the original three episodes as well as two additional episodes (City of the Damned, Hell’s Maw, The Dome of D’sparil, The Ossuary, and The Stagnant Demesne).

Gameplay-wise, Heretic is as simple and as challenging as Doom. The game is atmospheric, but the graphics are a little muddy and lack contrast. The level designs are pretty good, though, and most of the fun comes from figuring out the route to the exit. The controls are a little archaic, with mouse and keys used in an old-school way and players used to modern shooters may take time to adjust to them. You can’t jump in Heretic, but you can ‘fly’ up and down, which I guess is something.

The music in Heretic is a MIDI-only soundtrack, so is a little warbley, although the sound effects are good, with randomised ambient sounds and noises, such as evil laughter, chains rattling, distantly ringing bells, and water dripping – in addition to the background music – to enhance the atmosphere.

See also: Hexen II and Heretic II

More: Heretic on Wikipedia
Steam: Heretic/Hexen Collection on Steam
GOG: Heretic/Hexen Collection on GOG.com