Various Cheats
During gameplay, press Tab and enter any of the following "Codes":

nwcagents = Fill Empty Slots with 10 Black Knights
nwclotsofguns = Gain All War Machines
nwcneo = Gain a Level
nwctrinity = Fill Empty Slots with 5 Archangels
nwcfollowthewhiterabbit = Max Luck
nwcnebuchadnezzar = Unlimited Movement
nwcmorpheus = Max Morale
nwcoracle = Reveal Puzzle Map
nwcwhatisthematrix = Reveal World Map
nwcignoranceisbliss = Hides World Map
nwctheconstruct = Gain 100,000 Gold and 100 of Each Resource
nwcbluepill = Lose Game
nwcredpill = Win Game
nwcthereisnospoon = Gain 999 Mana and All Spells
nwczion = Gain All Buildings
nwcphisherprice = Change Games Colors to a Wierd Color Scheme

Cheat Menu
Start the game with the command-line parameter /nwcgrail (ie, "C:\SoD\homm3.exe" /nwcgrail). Then during gameplay and while in Windowed mode, press F4