Zork III

1. In version 10, if you READ a takeable object you pick it up, even if you shouldn't be able to: you can READ PILE to take the pile of valuables from the man, or READ RING to take it out of the cage (they stay invisible).
2. In version 10, TURN DIAL says, "You certainly can't turn it with a ." Version 12 says, "You can't do that!", which is misleading at best.
3. In version 10, you can try to UNLOCK any random object WITH KEY and get the message, "The key, which initially seemed certain to fit the lock, seems to change shape and will not enter the keyhole.", regardless of whether the object has a lock or not.
4. In version 10, the response to EXAMINE AQUEDUCT is, "The aqueduct is large and impressive. It was probably was the major method of water transport in the Empire."
5. In versions 10 and 12, if you're carrying nothing, then GIVE someone ALL causes a crash. Frotz exits with, "Fatal error: Stack overflow".
6. In versions 10 and 12, at Underwater, if you GET AMULET when you already have it, you have a chance of getting the response "The golden amulet is yours for a moment, but drops from your grasp." You still have the amulet.
7. In versions 15 and up, if the bread is present but not in your main inventory (even if you're carrying it in the open chest), then EAT BREAD produces no output. The bread stays where it is.
8. In versions 15 and up, if you try to burn the book when you're holding it you get, "I don't think you can burn a very ancient book.", though it burns "in a dazzling display of color" if you're not holding it.
9. In all versions, you can carry around the chest after tying the rope to it at Cliff Ledge, if you THROW CHEST OFF LEDGE. If you then go down and pick up the chest, you can carry it anywhere, except if you go back to Cliff Ledge. Trying to leave Cliff Ledge with it will still stop you with, "You can't go anywhere holding that chest. The rope is tied around it!". You can also UNTIE ROPE at Cliff Ledge when the chest is elsewhere.
10. In all versions, when the hooded figure appears, if the open chest is present you can PUT HOOD AND CLOAK IN CHEST. Now the figure doesn't have them anymore, and you can pick them up normally, but they don't show in your inventory or the room description. This allows you to get these items without scoring the point for attacking the figure. Once you've taken the hood from him this way, there is apparently no way to make the hood and cloak appear. If these are all you are carrying, then INVENTORY gives no output. If you only PUT CLOAK IN CHEST, then when you defeat him the normal way the cloak appears on the ground.
11. In all versions:

     >THROW GUARDIANS AT GUARDIANS
     
     The Guardians of Zork falls in front of the guardians, who destroy it 
     in perfect unison. Satisfied, they resume their posts.
    

    Anything in scope can be thrown at them for the same effect. Similarly:

     
     >THROW BOAT AT OCEAN
     
     The Viking Ship falls into the ocean and is lost forever.
    

    --Allen Garvin
12. In all versions, the game uses an array to store objects that you drop in a particular 'room' in the maze. The entire maze is actually represented by just one object, and anything you drop is removed from the game when you "move" in the maze. Then when you go back to that part of the maze, it moves the objects stored in that part of the array back to the maze. The problem is, the double-dimensional array only has 8 slots for each maze room. If you drop more than 8 objects, it messes up the array. You can go east and find some of the objects. If you drop them and there's a wall to the east, you can lose the items forever. --Allen Garvin
13. In all versions, if you're carrying the open vial you can THROW LIQUID AT something to put it on the floor. After you do this, the room description includes the silly message, "There is a heavy but invisible liquid here."
14. In all versions, it's possible to take the "pile of assorted valuables" from the man at Cliff Ledge. You can PUT PILE IN CHEST, or if you refer to the pile before he leaves then you can GET IT once he's gone. This object doesn't show in your inventory or the description. If you put it in the chest and close the chest while he's there, then he continues to examine the valuables.
15. In all versions, objects intended to be worn are always shown as worn when in your inventory--or in a container! For example, if the amulet is in the open chest, then your inventory or the room description includes, "The chest contains: A golden amulet (being worn)".
16. In all versions, when the man asks you to tie the rope to the chest, if you GET ROPE he "points to the chest near you on the ledge.", even if you're holding the chest, or have already thrown it off the ledge!
17. In all versions, if you tie the rope to the chest when the man asks you to, then when he comes back and tells you to grab onto the rope, if you say MAN, HELLO, he says, "What's that you say? I can't hear you very well. Just tie the rope to the chest and we can chat afterwards!", although the chest is gone. --Torbjörn Andersson
18. In all versions, at Key Room, you can move the manhole cover repeatedly. Each time the hole is revealed again.
19. In all versions, you can SMELL VIAL and even DRINK FROM VIAL when it's closed. --Torbjörn Andersson