This cheat works on All difficulties, including the Toughest difficulty. It will only work with inventory items only. To do it, pick up an item, then quickly open up the Hexen 64 Game Menu, Temporarily save the game, then reload it. Whalla! You will have two of the same item. You must time it right to get the same item twice. It can be repeated more than once until you need as much as you want.