Zork I

1. In version 2, you can APPLY many visible objects TO an open, empty container. Doing this with immovable objects often locks up the program: APPLY ME TO MAILBOX or APPLY CHIMNEY TO TABLE are good examples.
2. In version 2, when you throw the sword or nasty knife at the troll, it says he catches it and being momentarily sated, drops it to the ground. However, the sword or knife is not actually moved. You still have it in your possession after the throw. --Allen Garvin
3. In version 2, when you are at Cellar with the trap door open, OPEN TRAP says, "The door is locked from above."
4. In version 2, there is an error in the message for trying to CUT something WITH a non-sharp object. For example, CUT SWORD WITH GARLIC says, "I doubt that the "cutting edge" of a sword is adequate."
5. In version 2, there is no output if you BREAK something WITH an untakeable object.
6. In version 2, if you are at Dome Room with the rope tied to the railing, then JUMP gives no output.
7. In version 2, you can take the chalice when the thief is conscious.
8. In versions 2 and 5, you can carry the water in the brown sack. They were careful to keep PUT WATER IN SACK or POUR WATER IN SACK from working, but you can APPLY WATER TO SACK. You can even drink from the sack!
9. In versions 2 and 5, you can take the axe away from the troll using EAT AXE, READ AXE, or a number of other commands. It doesn't show in your inventory, or in the room description if you drop it. The troll will still bar your passage.
10. In versions 2 and 5, FILL something WITH something other than WATER gives no output.
11. In versions 2 through 20, you can repeat the exorcism. After you've completed the exorcism, every time you READ BOOK at Entrance to Hades you get the same message about the spirits fleeing, even though they're gone.
12. In versions 2 through 26, if you blow out the candles in an otherwise dark room, then the room stays lit.
13. In versions 2 through 28, one message you can get from the thief claims that "he quietly abstracted all valuables from the room and from your possession", but he can leave some behind. In version 30, "all" was changed to "some".
14. In versions 15 through 30, GO AWAY something has the same effect as GO something in versions 2-5: you're sent to a random location.
15. In versions 15 through 30, if the deflated boat is in the room, not in your inventory, then FILL BOAT says, "With a [garbage]? Surely you jest!"
16. In versions 15 through 30, if you knock out the troll, take his axe, then he wakes up, then GIVE AXE TO TROLL says, "You would have to get the bloody axe first, and that seems unlikely."
17. The behavior of the "Teeth Overboard" bug is interpreter-dependent. In the Infocom interpreters, versions 2 through 30 give strings of garbage in response to EXAMINE OVERBOARD.
18. In versions 2 through 30, you can get the raft and the pile of plastic at the same time using the "IT" bug. You can create this situation with either INFLATE PILE WITH PUMP or DEFLATE BOAT, followed by GET IT. If you leave one of these 2 objects somewhere and then make it elsewhere from the other, the copy you left disappears. Objects you leave inside the inflated raft appear inside it wherever you make it.
19. In versions 2 through 30, you can carry around the water without a container. If the bottle, with water in it, is in the same room with you, the command EAT WATER produces, "(Taken) I'd like to, but I can't get to it." You can get similar results with READ WATER, LOCK ME WITH WATER, UNLOCK ME WITH WATER, LIGHT WATER, LIGHT ME WITH WATER, RING WATER, BREAK ME WITH WATER, or TURN OFF WATER. Now the water is in your inventory, and you can do many things with it: EXAMINE, THROW, DROP, POUR, etc. However, you can't DRINK it; you get, "I'd like to, but I can't get to it." You can also PUT it almost anywhere, even back in the open bottle, but only if you're holding it; otherwise, "The water slips through your fingers."
20. In versions 2 through 30, BITE is apparently a synonym for KICK. If you say BITE GARLIC in versions 2 through 28, you get, "Kicking the clove of garlic doesn't work." (or "...doesn't seem to work.", or "...has no effect.", or "...isn't notably helpful.") In version 30, "Kicking" was changed to "Annoying". In version 75 and up, BITE works as EAT.
21. In versions 2 through 30, if the bottle doesn't have water in it, then THROW BOTTLE AT CHIMNEY (or some other feature that happens to be in the room, such as CASE or STAIRWAY) gives, "The bottle hits the far wall and shatters. You're not carrying the glass bottle."
22. In versions 2 through 30, if the open, full bottle is in the room, not in your inventory, then GET WATER picks up the bottle, but gives no output.
23. In versions 2 through 30, if you push the blue button and then wait in Maintenance Room, the rising water will eventually drown you, even if you're in the boat.
24. In versions 2 through 30, if you open the grate from Grating Room without having removed the pile of leaves, then the grate is still not visible at Clearing, and nothing you do at this point can make it visible.
25. In versions 2 through 30, if you open the grate without having removed the pile of leaves, then every time you OPEN GRATE the pile of leaves falls into Grating Room--even after a failure message telling you the grate's already open!
26. In versions 2 through 30, you can GIVE things TO MIRROR, but this just drops them on the floor.
27. In versions 2 through 30, there's no check for things held when throwing things at the cyclops. For example, you can THROW GRUE AT CYCLOPS and make "a lurking grue" appear in the room. --Allen Garvin
28. In versions 2 through 30, a strange memory corruption is triggered when the troll is disarmed and cannot recover the axe. It happens when you get the message, "The troll, disarmed, cowers in terror, pleading for his life in the guttural tongue of the trolls." Two bytes in the low memory are overwritten with the pointer to a string. In versions 2 and 5, this changes the parent and sibling objects of the nest. Trying to take the nest then locks up most interpreters; Bocfel exits with the message: "fatal error: malformed object table: parent has no children". Moreover, in version 5 the descriptions of many rooms are printed when one is up the tree (because the sibling of the nest is now a room). In the other versions, the changed bytes are in the table with the frequently used strings. In version 15, "narrow " becomes "narroizx'.1 ", showing in the description at North of House. In versions 20 through 28, "Cyclops " is corrupted, as you can see by going to Cyclops Room. Finally, in version 30, "but " changes to "but E". --Alessandro Giassi
29. In versions 2 through 30, EXAMINE CHALICE says, "The chalice is closed." PUT something IN CHALICE says, "The chalice isn't open.", but you can open it.
30. In versions 2 through 30, if there is something takeable at Temple, then GET ALL lists "prayer:" with a failure message.
31. In versions 75 and 76, if you die while holding a lit match, then you find and pick up the matchbook once you're resurrected, then it stays lit permanently, as long as you don't light another or do something to put it out.
32. In versions 75 and 76, if you push the blue button and then get in the boat, you die, supposedly carried over the falls by the rising water. However, this happens no matter where you are, at least for a number of turns after pushing the button. You can do it as far away as The Troll Room.
33. In versions 75 and 76, if you're in a location with water (where you could fill the bottle) and the bottle is empty, then DRINK WATER says, "You have to be holding the [garbage] first."
34. In versions 75 and 76, GET LEAFLET FROM MAILBOX says, "It is securely anchored."
35. In versions 75 and 76, at Sandy Cave, you can DIG SAND WITH anything in your inventory.
36. In versions 75 and 76, if you are in the boat at Canyon Bottom, then LAUNCH BOAT produces no output. --Marco Cavagna
37. In versions 2 through 76, LIGHT MATCH subtracts 1 from the number of matches remaining before checking to see if there are any. Thus, COUNT MATCHES will give you a negative number if you keep lighting them. To take this to an extreme, if you LIGHT MATCH 32774 times, you suddenly have a lot of matches.
38. In versions 2 through 76, THROW something AT BOTTLE gives the same response as THROW BOTTLE AT something: "The bottle hits the far wall and shatters.", but it is the other object that is removed. In versions 2 through 30, you don't even have to be holding the object, so you can use this to destroy almost anything.
39. In versions 2 through 76, if you're carrying the sword and a full inventory, then trying to take the rusty knife produces:

    As you pick up the rusty knife, your sword gives a single pulse of blinding blue light.
    Your load is too heavy.

    Version 88 changed "pick up" to "touch", but TOUCH KNIFE still gives a default message.
40. In versions 25 through 88, making the parser ask two questions about the same command can confuse it. For example, if you are in the Maintenance Room, BREAK BUTTON produces the question, "What do you want to break the button with?" If you answer SACK, for example, then it asks, "Which button do you mean?" Answering with a valid button color produces, "Trying to destroy the brown sack doesn't work." (In versions 75 through 88, it says, "Trying to destroy the brown sack with a brown sack...") THROW SACK asks, "What do you want to throw the sack at?". If you answer BUTTON, then answer the next question with a valid button color, you get, "You're not carrying the [color] button." In versions 75 through 88, it asks, "Which button...?" twice, and uses your second answer to produce, "You don't have the [color] button." Versions before 25 handle all of this nonsense correctly.
41. In versions 2 through 88, you can bypass the torch/dumbwaiter puzzle. To enter Drafty Room, you can only carry items of size equal or less than 4, but the brown sack from the kitchen is size 3 and capacity 15. Put the candles in it and light them, and you can walk into Drafty Room and have light. In versions 75 and up, this works only if you extinguish and relight the candles. --Allen Garvin
42. In versions 2 through 88, at Stone Barrow, if you examine the door you are told, "The stone door is closed.", but the room description says it is open, and you can still go west through it and win the game. --Marco Cavagna
43. In versions 2 through 88, at Dome Room, JUMP kills you if the rope is not tied to the railing. --Torbjörn Andersson
44. In the Solid Gold version only, you can THROW ME OVER CLIFF.
45. In the Solid Gold version, SIT is treated as the command UP.
46. In the Solid Gold version, there is a buggy response to PLAY ME:

    You become so engrossed in the role of the you that you kill yourself, just as he might have done!
     has no effect.
    
        ****  You have died  ****
    

    --Torbjörn Andersson
47. In versions 75 and up, you can THROW HANDS OVER CLIFF.
48. After you destroy the painting, it has no more points for putting it in the trophy case, but you still get 4 points for taking it. If you haven't taken the painting yet, it still displays the message, "On the far wall is a painting of unparalleled beauty". Also, it can be destroyed multiple times. --Allen Garvin
    These problems happen in versions 75 and up. As far back as version 2, there was a routine to handle DESTROY PAINTING WITH a weapon, but it was unreachable until version 75.
49. In versions 75 and up, if you extinguish the candles by pouring water on them, and then relight them with a match, they'll no longer have a flame. This bug works because there is an attribute for flaming objects, and an attribute for lighted objects. Different parts of Zork use them inconsistently. Trying to burn something with the candles, or pouring water over them, are the only inconsistencies. The gas room checks if the candles have light, as does the exorcism in the land of dead. Extinguishing the candles any other way removes the light attribute, but not the flame attribute. This itself presents no bugs because everything else seems to check for both the light and flame attributes before doing anything. --Allen Garvin
In versions 75 and up, the bird's nest is closable.
51. In versions 75 and up, in Grating Room, if you PUT something IN GRATING, it prints, for instance, "The skeleton key goes through the grating into the darkness below.", and of course just moves it into the room you're in. The slide in the cellar behaves the same way. --Allen Garvin
52. In versions 75 and up, EXAMINE WALL asks, "Which wall do you mean, the granite wall or the surrounding wall?" everywhere, even outside! Just about anything you try to do to the wall produces this question. Apparently, the surrounding wall exists everywhere in the game, but the granite wall doesn't, so this is very strange.
53. In versions 75 and up, you can POUR anything visible ON BELL to cool it off: HANDS, SPIRITS, whatever. The object is removed. --Torbjörn Andersson
54. In versions 5 and up, at Cellar, CLOSE TRAP responds, "The door closes and locks.", when it's already closed.
55. All versions have problems with solid objects in the closed bottle (except, apparently, version 2, which doesn't seem to let you PUT anything but water in the bottle). Anything you can PUT in the bottle, you can GIVE or PUT somewhere when it's inside the closed bottle. If the sack is in the closed bottle (possible in all versions but 2 and 52), you can OPEN or CLOSE it or PUT things in it, and you can SHAKE SACK to make them fall on the floor (in version 20 and up). If the sack is in the (open or closed) bottle, then you can't interact with anything in the sack. Even a simple EXAMINE GARLIC produces, "You can't see any garlic here!". However, you can use IT to refer to the garlic right after putting it in the sack. If you try to DROP or THROW something that's inside the closed bottle, you get, "The brown sack [or other object] is closed." In the Solid Gold version, you can even EAT GARLIC when it's in the closed bottle! (In other versions, you can't put the garlic in the bottle)
56. In all versions, there's a special object named 'overboard', that exists solely for the action THROW [object] OVERBOARD. There is no checking at all in the action routine to see if the player has the item. Thus anything in scope is fair game:

    >THROW GRUE OVERBOARD
    Ahoy -- lurking grue overboard!
     
    >THROW ME OVERBOARD
    Ahoy -- you overboard!
     
    >LOOK 
    Dam Base, in the magic boat
     You are at the base of Flood Control Dam #3, which looms above you and
     to the north. The river Frigid is flowing by here. Along the river are
     the White Cliffs which seem to form giant walls stretching from north to
     south along the shores of the river as it winds its way downstream.
     There is a you here. (outside the magic boat)
     There is a lurking grue here. (outside the magic boat)
      The magic boat contains:
       A tan label

    --Allen Garvin
57. In all versions, you can pick up the boat while you're in it, using EAT BOAT, etc. In the Solid Gold version, the game immediately locks up. In versions 75 through 88, the interpreter crashes; Frotz says, "Fatal error: Stack overflow". In versions 2 through 30, the game continues. The boat doesn't show in your inventory. If you're carrying nothing else, INVENTORY gives no output. You can still crash the game if you GET something or PUT BOAT somewhere. THROW something OVERBOARD puts it in your inventory. You can DROP BOAT or THROW BOAT, and it's still invisible. After you do that you can still GET OUT OF IT, but the boat and its contents are gone forever.
58. In all versions, jumping in the reservoir kills you, saying it was an unsafe place to jump. This is because the death-after-jumping is based on the hacky fact of whether the room's down property has a length of 2 or 4 bytes. --Allen Garvin
    You also die when you jump in the kitchen, and I never quite got why on earth the kitchen would be a dangerous place to jump around in. --Sophie Fruehling
59. In all versions, you can acquire both a broken canary and a working canary. After getting the thief to open the jeweled egg, when you've got the canary, climb back up the tree, put the egg in the nest, and drop the nest. It will crash to the ground, and you can go down and get a broken canary from the egg. It will exist alongside the working canary. For other parts of the code that break the egg, there's a function to remove the broken canary if the working canary is not in the egg. But this section doesn't check that! --Allen Garvin
60. In all versions, it's possible for the disarmed troll to get his axe back without being in the same room. If you knock the troll unconscious, take the axe and drop it in Cellar. Go visit the troll again, then return to Cellar. If you spend several turns at Cellar, there is a random chance that the axe will disappear. Now the troll has it again. The axe must be on the floor, and you must be in the same room as the axe. I don't know if it only happens at Cellar, but I haven't been able to make it happen in any of the other rooms you can get to while the troll is conscious.
61. In all versions, if you leave stuff in the reservoir while the lake is down, then turn the bolt to close the dam, only the trunk of jewels will disappear. Launching the boat onto the lake will show everything you left in the mud. --Allen Garvin
62. In all versions, dropping something at Up a Tree makes it fall to the ground, moving it to Forest Path--except if you drop the nest with the unbroken egg inside. In that case you're told the nest falls to the ground, but it actually stays at Up a Tree. Only the broken egg moves to Forest Path.
63. In all versions, when you're at Cellar with the trap door open, CLOSE TRAP responds as if the trap door were already closed.
64. In all versions, if you're in the forest above ground, and you throw the bottle at the grate or leaves or the tree, you get the same message about the bottle hitting the far wall, which obviously makes no sense in the forest. --Michael Coyne
65. In all versions, the game's standard response for trying to put water where it doesn't belong is sometimes used where it shouldn't apply. For example, If you say PUT WATER IN ME you get, "The water leaks out of the you and evaporates immediately." If you say PUT WATER IN WATER you get, "The water leaks out of the quantity of water and evaporates immediately." This works even with the bottle closed. You can get the same results in Zork II.
66. In all versions, destroying a container makes its contents disappear--for example, CUT BOAT WITH SWORD or THROW BOTTLE AT CHIMNEY.
67. In all versions, if you put things in the compressing machine besides the coal, and turn it on, then a diamond will be formed, and everything else undamaged. --Allen Garvin
68. In all versions, if you remove the label from the raft by some means other than GET or PUT (such as DROP, THROW, or CUT), then you deflate the raft and reinflate it, then you're told the label is in it when it isn't.
69. In all versions, opening the grating from the clearing side, it says:

     >LOOK
    
     Clearing
      You are in a clearing, with a forest surrounding you on all sides. A path leads
      south.
      There is a grating securely fastened into the ground.
    
     >OPEN GRATING
    
     The grating opens to reveal trees above you.

    --Allen Garvin
70. In all versions, you can lock the grate when it's open. If it is open but locked, then CLOSE GRATE says, "The grating is locked."
71. In all versions, at Up a Tree, objects on the ground (at Forest Path) are visible. However, because of the way it's implemented, they're only visible if there are at least two objects on the ground. --Torbjörn Andersson
72. In all versions, if you go to the Temple area for the first time via the granite wall trick, without ever having tied the rope to the railing, the rope is correctly missing from the description of the Torch Room, but trying to go UP from there results in the response, "You cannot reach the rope." --David Gargiulo
73. In all versions, if you happen to knock the thief unconscious in combat, you can take the chalice and even walk off with it, although the game won't let you pick up his stiletto or any other treasures the thief might possess. If you come back to the Treasure Room, and this time kill the thief, the game still tells you, "The chalice is now safe to take," even though it isn't present. --Marco Cavagna
74. In all versions, when the thief is unconscious, THROW KNIFE AT THIEF still says, "The thief makes no attempt to take the knife, though it would be a fine addition to the collection in his bag. He does seem angered by your attempt." --Torbjörn Andersson