On Puzzles in Interactive Fiction

I recently participated in a one-on-one interactive fiction competition in which I served as Iron Chef Inform 7. I wrote a game called “The Van der Nagel Papyrus” which, if you haven’t played it, you will find much more interesting than this dumb post.

I wrote something to wrap up my thoughts on “The Van der Nagel Papyrus,” and I was about to post it here, but it occurred to me that some of those thoughts proceeded from something else I wrote about five years ago. So, let us turn back the clock…

A fellow IF author emailed me about constructing a taxonomy of text adventure puzzles: puzzles that require a verb, puzzles that require an item, puzzles that require interacting with an NPC… Something about the idea didn’t sit right with me, and I wrote the following in response. (A “frame challenge” like this is probably not a pleasant thing to have land in your inbox, so it is unsurprising that my interlocutor never emailed me back.)

To me, the specific actions involved, or whether [the thing you need to solve a puzzle] is a noun or a verb, isn’t as useful a way to categorize puzzles as their relationship to the player’s experience. Like, jumping over a pit:

  • For Mario, this is the primary, elemental challenge. But after you do it enough times it becomes meaningless. Mario’s jump is tuned to be useful and predictable and fun.
  • But Arthur, the knight in Ghosts ’n Goblins, sucks at jumping. Even though he’s basically a Mario guy who runs from side to side and jumps! Getting him to jump over a pit is a nightmare. And it’s not because they did a bad job of making the game—they designed his jump to be more challenging.

The “meaning” of jumping over a pit depends on all this physics stuff and control schemes, so it can mean different things in different contexts. But let’s talk about jumping over a pit in IF, where all the gymnastics are in your head. First, take a Twine game that says

A pit separates you from the far end of the room. There are spikes at the bottom of the pit. You could probably jump over it…

Well, this is not a puzzle. All you can do is click on the word that makes you jump. But compare that to an Inform 7 game where the room description is

A pit separates you from the far end of the room. There are spikes at the bottom of the pit. You could probably jump over it…

This is almost kind of a puzzle, because the player has to draw the connection from reading “jump over” to typing in JUMP OVER PIT.

You can complicate it a little if you move the text “There are spikes, you could probably jump over it” into the response to EXAMINE PIT, forcing the player to observe the situation before the solution is handed over. Or you can cut out the clue entirely, and now the player has to come up with JUMP OVER on their own.

This might seem like a simple spectrum of puzzle difficulty. But you can draw the same spectrum for puzzles where you BREAK WINDOW or PUSH TREE or PUT QUARTER IN SLOT—and my point is that a puzzle where the text says “you could jump over that pit” is more similar for the player’s experience to a puzzle where the text says “you could put a quarter in that slot” than it is to a more opaque pit-jumping puzzle.

BECAUSE, and now I am figuring something important out, the player isn’t the one jumping over the pit. The gymnastics, like I said, are in your head. The IF player doesn’t unlock doors or cast spells. The IF player decides what to do and then types it out. And I think a very useful taxonomy of puzzles can be built out of analyzing what the player does:

  • Does the player need to know something?
  • Does the player need to try something?
  • Does the player need to notice something?
  • Does the player need to be creative?
  • Does the player need to apply logic?
  • Does the player need to do something that seems self-destructive or undesirable?
  • Does the player need to do something else first?

Well, no one ever got around to writing up that very useful taxonomy. But the notion that “the gymnastics are in your head” has stuck with me ever since. In parser games (and in other forms of IF, and to some extent graphical games, and indeed non-game media, but I can only speak with the authority of an Iron Chef on parser games), a huge amount of the action is internal to the player/reader—not just when it comes to solving puzzles, but imagining a world, piecing together a story, and understanding whatever it is that the author is communicating.