There aren't many codes for this game but here is what I found.
Take all of the items in the dragon's room - Go in and take the shield. Take three items. Leave and go back into the dragon room. Take the other four items. If you try to take all eight at once the shield will melt.
This works on all versions of the game.
I also have some Game Genie codes but I can't find the paper I wrote them on. I will add them here when I find them.
I found a glitch one time but had trouble reproducing it but I now know how to do it. This is called the glitched torch number trick. Go collect 9 torches. Hang around the dragons den with one torch lit and wait for the torch sound to come on. Quickly go out of the room into the room with the underground lake and use a torch. 50% of the time, the torch number will go up to 90. But if you use a torch the number will go back to nine. Remember, you have to do that stuff quickly for it to work. Very quickly.
Note: this does not work for Shadowgate Classics and was not tested on the Amiga or Mac Shadowgate.
