Inside the puzzle design: cryptograms, lateral thinking, observation

The puzzle design worksheet for Cora's Atlas is a shared spreadsheet on the free tier of a service we will not name, and the first column of it is category. We have three. Every puzzle we ship belongs to one of them, and every puzzle we cut belonged to one of them too. This is the dispatch where we show the worksheet.

1. The three categories of puzzles in Vellestria

A cryptogram asks you to decode a visible cipher. The cipher is in front of you the whole time. You are not being asked to guess what it says; you are being asked to read it. The work is in the substitution table, or the celestial alphabet, or the wax seal that means a different word in winter than it does in spring. Our cryptograms always make the alphabet visible somewhere on the screen. We are not trying to hide the rule. We are trying to teach you the rule and then ask you to apply it under a small constraint of attention. The boss puzzle that closes the Vellestria saga, The Sundered Coordinate, is the cleanest cryptogram in the published set so far: five symbols from Lambert Verras's 1965 cipher are laid out below a notebook page, and you have to pick the one Theodor used to mark the coast of the Sundered Isles.

A lateral-thinking puzzle does the opposite. It hides the rule in plain sight, lets you reach for the obvious answer, and then quietly turns the obvious answer wrong. The cryptogram says here is the rule, apply it. The lateral puzzle says the rule you assumed is not the rule. You solve it not by computing, but by re-framing. Inès's Morning Riddle is the first lateral puzzle in Chapter 1, and it is also the puzzle that most often gets reported to us as "broken" by players who, when they read the solution, write back to apologise. (The answer is name. It is not broken.)

An observation puzzle asks you to look at the scene again, and then again. The rule is not in the alphabet or in the framing; it is in the difference between two things that are almost the same. Four copies of a constellation drawing, one of them right. Six pages of a moon almanac, one of them wrong. The puzzle gives you a reference and a population, and you find the page that does not belong. The mechanic is light. The craft is in the choice of what differs. A good observation puzzle has one disqualifier per wrong answer and no false positives on the canvas; if you find yourself adding three "almost" details, the puzzle is broken. Six Pages from the Almanac is the cleanest one we have shipped.

Three categories. Every puzzle we draft sits in one of them on the worksheet before anything else gets filled in. We have tried a fourth category twice. Neither attempt survived the week.

2. Walking through the worksheet, one puzzle from each category

This is where we show the iteration. Some of it happened on paper, some in arguments over coffee, and some the morning after a draft shipped and we read it on the live site and winced. None of it is glamorous. All of it is how the work got made.

The cryptogram: The Sundered Coordinate

The first draft of The Sundered Coordinate was a thirty-six-letter substitution table. Lambert Verras's full 1965 cipher, every symbol matched to a Latin letter, with the player asked to decode a five-word phrase scratched into Theodor's notebook margin. The phrase translated to "I have found the islands". It was a perfectly fine cryptogram. It was also a perfectly dead one. The puzzle gave you a table and a string and asked you to do the work that any twelve-year-old with a pencil can do in eight minutes. The puzzle was the cipher; the cipher had nothing to do with Theodor, or the boat, or the fog, or the moment of arrival.

We cut it the morning we shipped Chapter 7. What survived was the cipher itself, kept in canon because earlier puzzles already referenced it, and the idea that Theodor had used one specific symbol to mark one specific coordinate. Then we re-asked the question. Instead of decode the message, the puzzle became pick which symbol he chose. The player sees five constellations rendered as star-fields below the notebook page. Four mark things that do not move. One is the sail. The alphabet is still doing its work, but the puzzle no longer asks you to look up letters in a table. It asks you to imagine Theodor on the deck of a schooner with the fog breaking, and to choose the symbol that describes what he was doing in that exact second.

The Layton vocabulary calls this kind of move "the puzzle that knows where it is". We just call it making the cryptogram about the person who wrote it. The answer to the published puzzle is voile. The phrase Eustache speaks before you choose, olunet veralath, means "the star is the sextant" in the brumeux tongue. We invented the brumeux tongue for the line. The line is the whole puzzle.

The lateral: Inès's Morning Riddle

Inès's Morning Riddle started life as four lines of verse and ended life as four lines of verse. What changed across six drafts was where the verse sat in the chapter. The first draft put the riddle on a wooden plaque above the door of the Sealed Compass, found by the player on their first walk through Old Town, with no character attached. The puzzle worked. The answer (name) landed. The player's success rate in our small playtest group was eighty percent. It also felt, to read it back, like a riddle you might find on a fortune cookie.

Draft two attached the riddle to Inès, but had her recite it ceremonially, like a guard at a gate. That was worse. The riddle now had a person but no occasion. The third draft attached the riddle to Inès and to the coffee — she sets down the cup, looks at the counter, and then, without looking up, says it. We added the line "Theodor used to ask this one to every new guest. Said it sorted the patient ones from the rest." That line is the whole lateral move. The riddle is not a riddle the player has to solve to advance the plot; it is a riddle the player has to solve to be recognised as someone Theodor would have liked. The mechanic stayed the same. The answer stayed name. The puzzle changed its species.

This is the part of lateral-thinking puzzle design we under-estimated for the first eighteen months: the obvious-answer-is-wrong move only works if you also know who is asking, and why, and what changes if you get it right. Without that, the lateral puzzle is a trick. With it, the puzzle becomes a small piece of dialogue you happen to be solving. Inès's post-dialogue line ("He asked it to every guest who made it past the first week. You did.") is doing more work than the riddle is.

The observation: Six Pages from the Almanac

Six Pages from the Almanac is the puzzle that almost taught us not to ship observation puzzles at all. The first version had eight pages, three anomalies, and a free-tap canvas — the player was meant to find all three breaks in the lunar cycle. We thought we were being generous. We had built a small forest of disqualifiers, the kind of "spot the difference" pile-up you find in newspaper back pages. Three different playtesters reported a different "right" answer. Two of them were not wrong. The puzzle had false positives, because eight pages of moon sketches generated enough cumulative noise that an attentive player could read a real-sounding rule into any of three pages.

We cut it back to six pages and one anomaly. We chose the anomaly that breaks the simplest possible rule: the moon waxes from new to full on the right side, then wanes from full to new on the left side. Page 5 of the published puzzle shows the right half lit after the full moon on page 4. That is the only error. The other five pages are valid. There is no ambiguity, no almost-right page, no second disqualifier. The puzzle now takes about ninety seconds to solve and Master Calix's post-dialogue line ("The moon does not change its rule. A chart that says otherwise is wrong.") is the puzzle's small justification for existing.

The observation category, we have come to think, is the one most likely to be made worse by ambition. Cryptograms get better the more careful the alphabet gets. Lateral puzzles get better the more specific the speaker gets. Observation puzzles get better the more you take out. We took out two pages, two anomalies, and one free-tap mechanic from the first draft of this one. The next one will probably lose more.

3. The hardest design problem in puzzle design

The hardest problem in narrative puzzle design is not the puzzle. It is the moment after the puzzle. The moment where the player has the answer, the screen has accepted it, and the next thing they see has to teach them something about the world they did not know one screen ago. Without that moment, the puzzle is a Sudoku. With it, the puzzle is a doorway.

The cleanest example we have shipped of this is the secret puzzle hidden behind a cracked floor tile in the cartography hall of the Library Quarter, called Master Branwen's Margin. The mechanic is almost nothing — you find a scrap of vellum, you read three lines of Branwen's handwriting (three children, four maps, one name on the spine), and you answer with the family name the scrap describes. The answer is Verras. A player who has read the Carnet knows it immediately. A player who has not read the Carnet learns, in the unlock dialogue Cora speaks aloud to the empty hall, that Marcus Verras had three children, that only the eldest carried the cartographer's name forward, that there are four canonical Verras maps, and that Branwen keeps the spine catalogue separate from the body catalogue for a reason that goes back to a 2005 argument we have not yet told the player about.

The puzzle is one question. The world that the puzzle is a doorway into is half a saga. The whole craft of puzzle design, for us, lives in that ratio. Every puzzle in Vellestria is the thinnest possible window onto the largest possible amount of canon. The window has to be solvable in under three minutes by a player who has never met the family. The view through the window has to reward a player who already has.

We do not always get the ratio right. Some of the puzzles we shipped early in Chapter 1 are pure mechanics — the answer is correct, the world behind it is wallpaper. We mark those in the worksheet so we know to come back to them when we re-issue Vellestria in the second pass. The worksheet has a column called world load, and the published average is lower than we want. Four nations still to come, four chances to do better.

Cora's note: The cracked floor tile in the cartography hall is not on any map. Branwen swept the corner clean when she installed me at the long table, and the tile gives a little when you stand on it just right. I have not told her I noticed. She has not told me she noticed me notice. That is also a puzzle, but it is not one we have written down on the worksheet yet.