What are the most "classic" parser puzzles?

I mentioned one of my favorite classic parser puzzles in another thread: the barrier that restricts your inventory in some way (e.g. you can’t go through the narrow passage unless you’re empty-handed) but you need an item on the other side (e.g. there’s a dark area that needs a light source). This shows up all over the place in old text adventures, and I love using it myself—it just lends itself to so many interesting variations, while fitting very nicely in the standard parser world model.

What are some other classic puzzles like this, that show up all over the classic text adventure scene with different variations and adaptations? The others that come to mind for me are:

  • Mazes that make mapping difficult, e.g. by having all the room descriptions look the same. This one’s old enough that Adventure even has a twist on it, with the “all different” maze!
  • Light sources that die after a certain amount of time. Scott Adams also has special opcodes for making this one work.
  • Doors that are locked with the key on the other side. This is another favorite; it’s less versatile than the inventory-constraining passage, but I love seeing clever solutions to it.

If I remember correctly there were two mazes of twisty little passages: “all alike” and “all different”! I think the former has truly identical descriptions, and the latter has subtle differences — “you are in a maze of little twisty passages”, “you are in a twisty little maze of passages”…


Yep! The “all alike” maze was created by Crowther, the “all different” maze was Woods riffing off it.


I think you’ve nailed the main ones that immediately come to mind for me. “Riddles” as a category is probably too broad, but maybe the one where there are two guards for two doors is specific enough to be a classic (though it’s maybe more an adventure game trope than a parser one particularly, I suppose).

Along similar lines, there are all those overcomplicated lever or button puzzles, where you’ve got five widgets to prod at, which light up seven lights, but each widget toggles two or three of the lights at once. And feeding a guard animal with (potentially poisoned, hopefully just with something soporific!) food.


well, what parser puzzle IF are more classic than Colossal Cave, Dungeon and Zork I/II/III ?

Best regards from Italy,
dott. Piergiorgio.

with identical room maze descs, the maze can be solved with crumbs (the oldest maze-solving scheme, harking back from the days of Theseus and Ariadne…) and with little twisty differences a maze can be mapped without dropping around items, so perhaps Woods has also accomplished the earliest known “nerfing” in videogame history ?

Best regards from Italy,
dott. Piergiorgio


Reading this, I realized that Anchorhead had every single one of these – in 1998. Not sure if that contributes anything, I just found it interesting/funny.


The oldest solution (Zork 2) is so heavily-used that it’s no longer clever. But it is really heavily used. Perhaps because it can be expressed so neatly in parser-English: PUT PAPER UNDER DOOR, PUT KNIFE IN KEYHOLE, PULL PAPER.

I suppose the most ancient parser puzzles are “learn a magic word, then you can use it” (XYZZY) and “you have to be carrying a particular item” (whether that’s a light source, smelly mud, grue repellant…)


I’m thinking more of puzzle concepts that can have multiple solutions across different games, which is why I’m not including “you need item X to open this door”, but I agree with “you can’t move in darkness without a light source” (or grue repellant or the like)—getting a light source has a lot of different permutations! That’s probably a better general one than “light source has limited life” from my original post.


I admit I absolutely hate these. They are used heavily used in early games like Colossal Cave Adventure to drive a sort of meta-game where the goal was to solve the game in the fewest moves, and definitely not on the first try.

Time (also food, drink, or sleep) limits work directly against the idea of open-world exploration, unless there is a way to circumvent them in a permanent or nearly permanent manner. Instead of exploring I find myself relentlessly reloading to optimize my move count. :frowning:


I don’t know that it’s a “puzzle” in the sense of having a deterministic solution, but dealing with thief-like NPCs that steal inventory was at one time all the rage.


Reaching through a small opening with a tool. E.g. stick in hole or newspaper under door.

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Killing things is a classic, for better or worse


With what, your bare hands? :joy:


Some type of machine you need to figure out how to operate.

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Choosing the best tool for the job.

  • Use the flaming torch when you can because it lasts longer than the battery-powered lantern.

  • The bridge troll can be bribed with any treasure, but if you hand over one you can magically retrieve later, you can still collect them all.

Quid pro quo: Feed the hungry animal and it might do a favor for you in return.

Digging deeper: The clue or item you need may not appear in a routine location description or even when you examine something. You might need to look under the rug or inside all of the desk drawers.


One of the classic puzzles that is perhaps best suited to the parser is realising you have to do a unique action you haven’t yet done. Typing it in gives you an “aha!” moment.

  • Lost Pig’s first puzzle is this
  • This is a notable moment in Photopia
  • Superliminal Vagrant Twin has an aspect of this with the planet travel system

Is this the sort of thing you’re thinking of?

  • Giving food or money to a beggar to get a reward.
  • Finding a trapdoor under a rug.
  • Getting past a troll that’s guarding a bridge.
  • Feeding a dog some meat or a bone to get past it.
  • Finding a way to get past a guard (lots of variations on this one).
  • Catching a mouse or a rat with cheese, perhaps by baiting a mouse or rat trap with it.

I’m sure there’s a better way to describe this, but I call this the “parity-breaking puzzle”: when there’s something like a door that can be in two states, and normally the process of getting to it leaves it in state A, but you need to get to it in state B.

The first example I always think of is from a point-and-click adventure game I played as a kid, with a bookcase that rotates to act as a door. Whenever you pass through it, it rotates 180 degrees along with you, so no matter which room you’re in you’re always on the same side of it; you need to find a way to get to the other side, by getting to the other part of the map without rotating the door.

Or, there’s a lever in a certain room that opens a door somewhere else, but seals off the room you’re currently in. So the puzzle isn’t how to open that door, it’s how to reach that door while it’s open. I think I’d call the gold nugget in Adventure a proto-version of this.

The puzzle that leads to the “second version” of The Wand would count too, I think.