Here are tips and cheats for Diablo: Hellfire

1) To duplicate items, first put the item you want to duplicate onto the ground. Then, walk away from it until it is on the edge of your screen(so you can still click on it). Next, put an item you do not care much about on your belt. Click on the item on the ground. At the exact time you pick the item up, click on the item in your belt (this may take a few tries). Open you inventory by pressing "I". Put the belt item in an empty spot in your inventory. If you have done this correctly, your belt item will become the item you wanted to duplicate. This also works for Diablo.
2) To unlock extra quests and characters, first download the latest patch for Hellfire. Next, create a text document in the hellfire directory called command.txt. In this file, insert this into the first line - multitest;cowquest;theoquest;bardtest;barbariantest (no hyphon). Now, you have unlocked multi-player (there is no Battle.NET), 2 new quests, and 2 new characters. The Bard is basically a Rouge, except he can hold 2 swords, and his skill is identify. The Barbarian can hold a 2 handed weapon and a shield and the same time. Unfortuneately, the Barbarian maximum magic level is 0.
3) To get a free rune bomb, do this. After Lester has given you the rune bomb, make sure that you have unlocked the extra quests and characters. Then, talk to Farnham the Drunk, and he go to blow up the hives, you now have an extra rune bomb. I have not yet found the usefullness of this cheat.