Heretic Cheats

Quicken        -  The same as God Mode in Doom. It's the path to invinciblity.
Massacre       -  Kills everything on the level.
Skel           -  Get keys.
Rambo          -  Get full health armor, and weapons recharge.
Engage         -  Level warp. Type "engage" and then the number of the level you wish to warp to.  
Kitty          -  This will let you walk through walls just like idclip for Doom II--just be sure 
                  toturn it off when yu want to pick up an item or activate a switch.
Cockadoodledoo -  We're not going to say what this one does, but you'll certainly get a
                  laugh when you try it out.