SERIAL

Puzzle Incident History

54 episodes · updated 2026-10-07

The history of puzzles is a history of inventions — and of incidents. Sam Loyd's prize hoax, worldwide crazes, city-scale mysteries: Toki records the moments puzzles shook the public, working from primary sources.

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Episodes

  1. Ep. 54
    Game of Life (1970) — A Grid with Two Rules Gained the Power to Compute
    2026-10-07

    In October 1970, Martin Gardner's Scientific American column introduced Conway's one-player game Life. It has two rules: birth and survival. In November an MIT team found the glider gun, overturning the conjecture that finite patterns cannot grow forever. We trace its history as far as sources allow.

  2. Ep. 53
    Hexaflexagone (1939) — Des chutes de cahier qui cachaient une face
    2026-10-06

    En 1939, Arthur Stone, étudiant à Princeton, plia des bandes de papier rognées et découvrit un hexagone dont les faces s'échangent. Feynman et Tukey comptaient parmi ses collègues. Martin Gardner le présenta en décembre 1956, et il devint très connu. Nous retraçons son histoire dans la limite des sources confirmées.

  3. Ep. 52
    Le tour du cavalier (vers 840) — Quand les échecs sans compétition sont devenus poésie et mathématiques
    2026-10-05

    Visiter les 64 cases d'un échiquier par des sauts de cavalier remonte à des manuscrits du IXe siècle et à la poésie indienne. Euler l'a traité en 1759, Warnsdorff a donné une règle en 1823, et le dénombrement a été confirmé en 1997. Voici son histoire d'après les sources vérifiables.

  4. Ep. 51
    La Tour de Hanoï (1883) — la légende des soixante-quatre disques, lancée par un mathématicien sous pseudonyme
    2026-10-04

    En 1883, le mathématicien français Lucas mit en vente, sous le nom de « professeur N. Claus de Siam », un jeu de disques et de trois tiges. Le nombre minimal de coups pour n disques est 2^n − 1. La légende des soixante-quatre disques représente environ 585 milliards d'années de calcul. L'optimalité pour quatre tiges a été démontrée par Bousch en 2014. J'en retrace l'histoire, dans la limite des sources que j'ai pu vérifier.

  5. Ep. 50
    Le problème des huit dames (1848) — Placer huit pièces sans qu'aucune n'en attaque une autre. Un échiquier que Gauss a aussi compté
    2026-10-03

    En 1848, le problémiste d'échecs Bezzel proposa de placer 8 dames sur un échiquier de 8×8 sans qu'aucune n'en attaque une autre. En 1850, Nauck en donna 92 solutions, et Gauss s'y attela aussi dans une lettre. En 1971, Dijkstra en fit un support d'enseignement du backtracking. Cet article retrace l'origine de cette question d'une seule ligne, dans la mesure des sources que j'ai pu vérifier.

  6. Ep. 49
    Sprouts (1967) — A Two-Player Game of Dots and Lines on Paper That Resists Solving
    2026-10-02

    In 1967 John Conway and Michael Paterson at Cambridge devised Sprouts, a pencil-and-paper game for two, and Martin Gardner's July 1967 column spread it. Join dots, add a new dot on each line, and the game must end. Computers have charted who wins for each starting size, yet a conjecture remains.

  7. Ep. 48
    Nim (1901) — The First Stone-Taking Game to Be Solved, and the Machines That Played It
    2026-10-01

    In 1901 Charles Bouton of Harvard named a stone-taking game 'Nim' and published its complete winning method. Write the heaps in binary, add column by column, and aim for zero: win and loss become visible. The logic grew into the Sprague–Grundy theorem and gave rise to game-playing machines, the 1940 Nimatron and the 1951 Nimrod. This essay traces what a solved game left to the history of puzzles and computing, using only facts that could be backed by sources.

  8. Ep. 47
    Hex (1942) — The Year a Hexagon in the Corner of a Newspaper Ruled Out a Draw
    2026-09-29

    In 1942, a hexagonal board appeared in a newspaper in occupied Denmark. Six years later, John Nash independently rediscovered it at Princeton. From a proof that the game can never end in a draw to the modern genre of "connection games" and the lineage of game-playing AI, this traces what Hex left behind.

  9. Ep. 46
    Instant Insanity (1967) — One Right Answer Among 41,472
    2026-09-25

    In 1967, Parker Brothers released a toy that was nothing more than four cubes stacked in a row: Instant Insanity. The rule was simple — make all four colors appear on every side of the stack. Yet there are 41,472 possible arrangements, and essentially only one way satisfies the condition. Its ancestor was a patented 1900 puzzle called the "Katzenjammer," known by the 1940s as "The Great Tantalizer." In 1947, a group of Cambridge students writing under a pseudonym solved that ancestor puzzle by turning it into a graph — colors as vertices, opposite faces as edges. This article traces the toy's origins, and how the tradition of treating puzzles as objects of computational-complexity theory reaches, half a century later, all the way to research on the Steam game Portal.

  10. Ep. 45
    Sangaku (1683) — Votive Tablets Hung at Shrines Not to Thank the Gods for a Solved Problem, but to Challenge the Next Visitor to Solve One
    2026-09-24

    Sangaku are geometry problems painted on wooden votive tablets and dedicated at shrines and temples in Edo-period Japan. The earliest dated record is from 1683, and the oldest surviving tablet dates to 1686. Some were dedicated without an answer, as a challenge to the next visitor; one from 1822 recorded what is now called Soddy's hexlet, 115 years before its Western discovery. The spirit of building figures with only a compass and straightedge still lives on in puzzle games like Euclidea and Ecocoru.

  11. Ep. 44
    Rush Hour (1996) — The Year a Wooden Traffic Jam Earned a PSPACE-Complete Proof
    2026-09-23

    Released in the US in 1996, the wooden sliding-block puzzle Rush Hour starts from one simple goal: slide a red car out of gridlock. In 2002 it was proven PSPACE-complete, and a quarter-century later it is still the subject of computer-science papers. This traces the history of the single board its inventor, Nob Yoshigahara, left behind.

  12. Ep. 43
    Eternity Puzzle (1999) — The Year a £1 Million "Unsolvable" Fell in Seven Months
    2026-09-22

    Eternity, a flat tiling puzzle released in the UK in 1999, was marketed as unsolvable behind a one-million-pound prize. Contrary to inventor Christopher Monckton's own estimate, two Cambridge mathematicians reached a solution in just seven months. 209 pieces, 10^500 possible arrangements, and a solution found by discarding the inventor's own "clues" — this article traces that story, and the line of complexity-theory research it started that now reaches into today's Steam puzzle games.

  13. Ep. 42
    Othello (1973) — The Year a Game Whose Patent Was Rejected Was Proven, Half a Century Later, to End in a Draw
    2026-09-21

    Othello: black and white discs on a green board, flipped by sandwiching the opponent's line. Goro Hasegawa of Japan sold it through Tsukuda in 1973. But the game had a 19th-century English forebear called Reversi, and the historical record includes two Englishmen publicly accusing each other of plagiarizing it. Hasegawa's own origin story changed too — the version he told at launch differs from the one he told from the 2000s onward. His attempt to register the rules (a Japanese utility model) was ultimately rejected, so no one has ever owned Othello's rules as it spread worldwide. In 1997, a computer named Logistello swept the reigning world champion six games to none. In 2023, mathematicians proved that perfect play by both sides ends in a draw. This piece follows the nearly 150-year lineage of a single flipping disc.

  14. Ep. 41
    Pyraminx (1981) — Designed Before the Rubik's Cube, Released to Ride Its Boom
    2026-09-19

    The Pyraminx is a tetrahedral twisty puzzle: each of its four faces is divided into nine triangles, and only the vertices and edges actually need to be solved. Its inventor, Uwe Mèffert, is said to have worked out the basic mechanism around 1971 — before Ernő Rubik even conceived the Cube in 1974. But Mèffert held off, securing patents in multiple countries, and only brought it to market in 1981 through Tomy, riding the Rubik's Cube boom he had arrived too early for. It reportedly sold over ten million units in its first year and roughly ninety million within three. Unlike the Cube, where every piece's move affects every other piece, the Pyraminx's four corner tips spin freely without touching the rest of the puzzle at all — a different design lesson about which parts of a mechanism actually need to be connected.

  15. Ep. 40
    Nine Linked Rings (Baguenaudier) (1872) — The Year an Origin-Unknown Ring Puzzle Turned Out to Use Binary Math 81 Years Before a Telegraph Engineer Patented the Same Idea
    2026-09-18

    Nine Linked Rings, or Baguenaudier: remove rings from a bar one at a time until the last one slides free. Its origin is said to be China, but nothing is settled; the earliest confirmed records are a 16th-century Chinese text and, around the same time, the writings of Italian mathematician Luca Pacioli. In 1872, Lyon mathematics enthusiast Louis Gros became the first to theorize the puzzle's solution as a binary table. The same idea was independently reinvented 81 years later, in 1953, when telegraph engineer Frank Gray patented what communications engineers now call the "Gray code." As a physical puzzle, a 1970 patent by William Keister became "Spin-Out," an early product of Binary Arts (founded 1985, now ThinkFun), still sold today. This piece follows the 150-year lineage of a single ring mechanism.

  16. Ep. 39
    The Seven Bridges of Königsberg (1736) — The Year Euler Erased the Map to Solve a Sunday Puzzle
    2026-09-17

    The answer is simple. In 1736, the mathematician Leonhard Euler proved that no walk existed that crossed all seven bridges of the Prussian town of Königsberg exactly once and returned to its start. The town's four landmasses were connected by 5, 3, 3, and 3 bridges respectively — all odd numbers. His paper, "Solutio problematis ad geometriam situs pertinentis," was presented on August 26, 1735, and published in 1741. By reducing landmasses to points and bridges to lines, Euler founded what became graph theory — the same logic taught in schools today as the rule for "one-stroke" drawing puzzles. This article traces how that 290-year-old proof still shapes the design of today's routing puzzle games, from Cosmic Express to Lyne to Mini Metro.

  17. Ep. 38
    Peg Solitaire (1697) — The Day a Game With No Inventor Became the Math of Proving "Unsolvable"
    2026-09-16

    On a cross-shaped board of pegs, you jump one peg over its neighbor and remove it, again and again, hoping to end with a single peg left. The earliest record of Peg Solitaire appears in 1697, in the French court periodical Mercure Galant under Louis XIV. No inventor is known. The popular legend that a prisoner in the Bastille devised it traces back no further than an English book from 1801, and puzzle historian John Beasley calls it unsupported by any earlier French source. In 1912 Ernest Bergholt found an 18-move solution to the classic problem; in 1982 Winning Ways for Your Mathematical Plays introduced the "pagoda function," a tool for proving certain positions mathematically unreachable. In 2007 the board resurfaced as puzzles inside Professor Layton and the Diabolical Box. This piece traces a single ruleset that has been played for over three centuries without ever needing a named inventor.

  18. Ep. 37
    Hitori (1990) — Why a Puzzle Too Hard to Catch On for 8 Years Is Still an AI Test Case in 2025
    2026-09-15

    Hitori — first published as a reader submission in Puzzle Communication Nikoli issue #29 in March 1990 — is a logic puzzle built from just three rules: no duplicate numbers, no adjacent black cells, and no disconnection. It was too hard to catch on at first, taking eight years to find its footing. Yet it was ported to the Nintendo DS in 2007, proven NP-complete by Robert Hearn and Erik Demaine in 2009, and in 2025 became the subject of an AI research paper on explaining puzzle solutions. This traces how far three reader-submitted rules have carried across 35 years.

  19. Ep. 36
    Mastermind (1970) — A Telecoms Engineer's Four Colors, Later Reborn as Fallout's Hacking Screen
    2026-09-14

    In 1970, Israeli telecommunications engineer Mordecai Meirowitz devised Mastermind, a game that reveals only a count of hits and near-misses from four hidden color pegs. Rejected by major toy companies, it was released by Invicta Plastics in 1971 and sold over 30 million sets within the decade. In 1976 Donald Knuth showed it could be solved in five moves or fewer, and in 2007 a Bethesda programmer built it directly into Fallout 3's hacking minigame. This piece traces how a half-century-old constraint — telling the player only a number, never the answer — still shapes puzzle design in the age of Wordle.

  20. Ep. 35
    The Decagon House Murders (1987) — The Debut That Answered Knox's Decalogue
    2026-09-12

    In 1987, Yukito Ayatsuji's debut novel The Decagon House Murders trapped university students - each bearing the name of a Golden Age Western mystery writer - inside a ten-sided mansion on a deserted island, igniting Japan's "Shin Honkaku" (new-orthodox) mystery movement. Behind it lies a rulebook for fair play with the reader: S. S. Van Dine's 1928 Twenty Rules and Ronald Knox's 1929 Decalogue. That same rulebook is still cited today, down to Ryukishi07's Umineko no Naku Koro ni, a mystery game sold on Steam.

  21. Ep. 34
    SameGame (1985) — The Grammar of Clearing Same-Colored Clusters, Born From a Reader Submission
    2026-09-10

    In 1985, a program called Chain Shot!, submitted to the Japanese magazine Monthly ASCII, wrote the rule of clearing adjacent same-colored blocks in one tap. Over the next forty years the rule kept changing its name — SameGame, Clickomania!, Jawbreaker — while becoming the subject of a solving algorithm in 2012 and an AI-reasoning benchmark in 2024. Its author's name has nearly been forgotten, but the rule itself lives on.

  22. Ep. 33
    Himitsu-bako (1894) — The Souvenir That Never Explains How to Open It
    2026-09-09

    In 1894, in a hot-spring town in Hakone, a wooden box took its familiar form. Under its geometric marquetry sat a mechanism that only opened through a fixed sequence of moves — with no instructions attached. This piece traces the same design grammar found in today's escape rooms back to a single 132-year-old box.

  23. Ep. 32
    Pigs in Clover (1889) — A Tilting Wooden Box That Stalled the U.S. Senate for a Season
    2026-09-08

    In 1889, a single wooden box brought the United States to a standstill. Under a sheet of glass, four tiny marble "pigs" sat in a spiral maze; the only tool was gravity, tilting the board to herd all four into the center pen. Senators and newspapermen alike stopped mid-sentence for it. The inventor was Charles Martin Crandall, who patented it on September 10, 1889. Two years later, puzzle writer Sam Loyd claimed he'd invented it himself, and for decades the record blurred. A craze that got itself mocked in a White House political cartoon deserves, I think, to be read again as one of the first mobile games.

  24. Ep. 31
    Eggerland (1985) — The Original One-Room Puzzle Where You Push Your Enemies as Eggs
    2026-09-06

    In 1985, a modest puzzle game appeared for the MSX home computer: Eggerland Mystery. Shoot an enemy to turn it into a pushable egg, then collect hearts to open the treasure box — a design built from just a handful of verbs, contained entirely within one room. HAL Laboratory refined that grammar across a run of Famicom Disk System titles, and in 1989 it crossed the ocean as Adventures of Lolo. Sitting in the producer's chair for those two years was a young Satoru Iwata, years before he became Nintendo's president.

  25. Ep. 30
    Shanghai (1986) — The Rules a Hospital PLATO Terminal Wrote
    2026-08-26

    In 1986, Activision released Shanghai, a simple puzzle of clearing mahjong tiles two at a time. But its roots trace to 1981, when a paralyzed student coded it on a hospital PLATO terminal. A historian's look at the 45-year lineage that followed.

  26. Ep. 29
    Book of Lenses (2008) — A Hundred Ways to Look at a Game
    2026-08-25

    Published in 2008, The Art of Game Design: A Book of Lenses introduced 100 questions for looking at a game. A historian's look at where that idea came from, and how it still reaches today's puzzle designers.

  27. Ep. 28
    The MDA Framework (2004) — Three Words Puzzle Designers Still Use
    2026-08-23

    In 2004, a few-page paper presented at an AAAI workshop reshaped the vocabulary of game design. Robin Hunicke, Marc LeBlanc, and Robert Zubek formalized Mechanics, Dynamics, Aesthetics. This piece follows those three words from Doug Church's unfinished 1999 homework, through a GDC workshop room, into the real project Oasis, and onto the shelf we now call Steam.

  28. Ep. 27
    Sudoku (1979) — How a Nameless Invention Conquered the World's Morning Papers
    2026-08-22

    In 1979, a puzzle called 'Number Place' appeared, uncredited, in an American magazine. This piece traces the 25 years it took to become Sudoku — refined by Japan's Nikoli, carried by a retired Hong Kong judge's homemade program, and finally landing in a London newspaper in 2004 — and the 'logic only, no guessing' design principle that still lives on in the 2024 Steam puzzle collection Islands of Insight.

  29. Ep. 26
    The Art of Computer Game Design (1984) — The First Book That Tried to Define What a Game Is
    2026-08-21

    In 1984, Chris Crawford — a game designer who had just been laid off by Atari — wrote a book: The Art of Computer Game Design. It was the world's first serious attempt to define a game itself, through four elements: representation, interaction, conflict, and safety. This essay traces the early-1980s context that produced the book, the small living-room gathering he started the following years that grew into today's GDC, and why his definition still fuels academic debate today.

  30. Ep. 25
    Hakoiri Musume / Klotski (1930s) — The Lineage of Blocks That Trapped Cao Cao
    2026-08-19

    In the West as a patent drawing, in China as a paper cutout re-enacting Cao Cao's defeat, and in Japan as a wooden toy called Hakoiri Musume — nearly the same sliding-block puzzle arose independently in three places between the 1890s and the 1930s, with no evidence any referenced the others. Martin Gardner published its 81-move optimal solution in Scientific American in 1964; Microsoft's Windows Entertainment Pack carried it to PCs worldwide in 1991. This is the record of that parallel evolution, up to 2021's Blockee on Steam, which names Klotski as its inspiration in its own words.

  31. Ep. 24
    Hashiwokakero (1990) — Thirty-Six Years of Logic Grown from Numbers Joined by Lines
    2026-08-18

    In 1990, Hashiwokakero debuted in Puzzle Communication Nikoli #31. Its rule — connect numbered islands with bridges until everything forms one network — grew out of an earlier prototype, "Ketsugoshu," that the same contributor "renin" had published in issue #28 the year before. In 2009 it was proven NP-complete; in 2004 it reached Simon Tatham's Portable Puzzle Collection ahead of any Steam release; and in 2023 Nikoli itself ported it to Switch, PC, and Xbox. This article verifies a 36-year lineage.

  32. Ep. 23
    Minesweeper (1990) — The Logic Puzzle Microsoft Built Into a Billion PCs
    2026-08-17

    On 8 October 1990, a small game shipped as one of seven titles in the Windows Entertainment Pack. From 1992's Windows 3.1 onward it came preinstalled on nearly every PC running Windows, and its lineage is said to trace back to Mined-Out, a 1983 ZX Spectrum game by British programmer Ian Andrew. This article follows the genealogy of a logic puzzle nobody set out to design as one — up to 2017's Tametsi, which stripped out the probability and returned the form to pure deduction.

  33. Ep. 22
    Mirror Isles / Skipping Stones to Lonely Homes (2014-2015) — How Two Free Jam Games Became Two Different Escape Islands, a Decade Later
    2026-08-06

    In 2014 and 2015, London puzzle designer Alan Hazelden wrote two free PuzzleScript jam games, Mirror Isles and Skipping Stones to Lonely Homes. By his own account on his website, the former is the spiritual ancestor of his 2020 commercial release A Monster's Expedition, and both games are also credited as one inspiration and starting point for Jonathan Blow's new game Order of the Sinking Star, whose demo appeared in 2026. This piece traces, using only the developer's own words, how two weeks-long free experiments fed into two very different commercial puzzle games over more than a decade.

  34. Ep. 21
    Nurikabe (1991) — A Ban on Two-by-Two, Borrowed from a Yōkai's Name
    2026-08-05

    In 1991, Nurikabe debuted under the pen name "renin" in the reader-development column of Puzzle Communication Nikoli #33. Its four rules — size islands by number, connect the rest into a single black sea, and never allow a two-by-two black block — weren't even expected to catch on by the magazine's own editors. In 2004 it was proven NP-complete; its "no two-by-two" rule was inherited by LITS; and in 2025, Steam's Nurikabe World brought the puzzle back under its own name. This article verifies a 34-year lineage.

  35. Ep. 20
    Masyu (2000) — The Loop of Black and White Pearls Born from a Misreading
    2026-08-03

    In April 1999, Puzzle Communication Nikoli issue #84 published a puzzle format called "Pearl Necklace," using nothing but white circles. In 2000, issue #90 added black circles and renamed it "White Pearl, Black Pearl," completing the logical skeleton Masyu still uses today. The official name "Masyu" wasn't settled until 2003 — the result of Nikoli's president misreading a kanji, an accident that simply stuck. With sources, we trace how a grid using no numbers or letters survived 26 years across an NP-completeness proof, official console ports, and an open-source implementation.

  36. Ep. 19
    Soma Cube (1933) — Twenty-Seven Fragments Born in a Quantum Mechanics Lecture
    2026-08-02

    In 1933, half-listening to a lecture on quantum mechanics in Copenhagen, Piet Hein enumerated every non-convex fragment that could be made by joining four or fewer unit cubes by their faces, and produced the seven-piece, 27-cube Soma cube. Popularized worldwide by Martin Gardner's 1958 column and commercialized by Parker Brothers in 1969, its 240 solutions were later hand-solved by John Conway and Michael Guy, and its debt is acknowledged by none other than Rubik's Cube inventor Erno Rubik. This piece traces ninety years of a solid-dissection puzzle lineage.

  37. Ep. 18
    Get Off the Earth (1896) — The Patent Sam Loyd Took Out on a Miscount
    2026-07-31

    In 1896, puzzle columnist Sam Loyd patented a rotating vanishing puzzle called Get Off the Earth. This piece traces the real mechanism behind its disappearing figure, its 1880 predecessor The Magic Egg Puzzle, its roots in Loyd's 1858 Trick Mules, and the trail this rearrangement trick has left in optical-illusion puzzles today.

  38. Ep. 17
    Numberlink (1897) — d'une rubrique de puzzles dans un journal à l'ère de Flow Free et Zip
    2026-07-30

    En 1897, le concepteur de puzzles Sam Loyd publia « The Puzzled Neighbors » dans le Brooklyn Daily Eagle. En 1917, Henry Ernest Dudeney l'affina en un puzzle pour automobilistes dans son propre livre ; dans les années 1980, Nikoli l'implanta au Japon sous les noms d'Arukone et de Numberlink. En 2012, Flow Free, de Big Duck Games, le transforma en points colorés et en tuyaux, dépassant les cent millions de téléchargements ; en 2025, cette filiation atteint le puzzle quotidien Zip de LinkedIn. Cet article retrace comment une règle vieille de plus de cent vingt ans — tracer une seule ligne sans la croiser — a survécu jusqu'à aujourd'hui.

  39. Ep. 16
    Pentomino (1965) — comment la forme à cinq cases nommée par Solomon Golomb est devenue Tetris
    2026-07-29

    En 1965, le mathématicien américain Solomon W. Golomb rassemble dans son ouvrage « Polyominoes » la théorie des douze figures obtenues en assemblant cinq carrés, les « pentominos ». Le nom remonte à une conférence donnée à Harvard en 1953 ; en 1957, la chronique de Martin Gardner le fait connaître au grand public ; en 1975 paraît une traduction russe. Puis, en 1984, un jeune homme de Moscou, Alexey Pajitnov, s'appuyant sur ses souvenirs d'enfance des pentominos, fait bouger des figures sur un ordinateur expérimental, et Tetris voit le jour. Cet article retrace le parcours de plus de trente ans qu'il a fallu à une forme de cinq cases pour faire le tour du monde.

  40. Ep. 15
    Yajilin (1999) — A Board Where Two Rule-Systems Were Grafted Together
    2026-07-28

    In July 1999, Puzzle Communication Nikoli issue #86 introduced Yajilin, a hybrid pencil puzzle that grafted the "draw exactly one loop" grammar established by 1989's Slitherlink onto a black-cell-counting rule. It reused the arrow-and-number cell from a puzzle published just before it, Yajisan-Kazusan, and by 2005 had already been adopted, as "Arrow Ring," into the US qualifying round of the World Puzzle Championship. From official Xbox and PS Vita ports to a dedicated 2025 mobile app called Loopr, we trace, with sources, 26 years of this grid's survival.

  41. Ep. 14
    Kakuro (1966) — De Cross Sums à la « croix additive », une grille d'additions inchangée depuis soixante ans
    2026-07-25

    Le Kakuro, appelé Cross Sums dans le monde anglophone, est né en 1966 comme un simple puzzle des éditions Dell, aux États-Unis. Dans les années 1980, Nikoli l'a importé au Japon sous le nom de « croix additive » (kasan kurosu), avant qu'il ne se répande dans le monde entier en 2005, réexporté pour ainsi dire via le quotidien The Guardian. Cet article retrace, à travers les pages d'époque comme les fiches actuelles de la boutique Steam, les raisons pour lesquelles cette grille consacrée à l'addition — ni mots croisés, ni sudoku — a traversé soixante ans de changements de support sans jamais modifier sa règle.

  42. Ep. 13
    Slitherlink (1989) — Loop-Closing Logic Born From a Two-Player Paper Game
    2026-07-23

    In June 1989, barely half a year into the Heisei era, Puzzle Communication Nikoli #26 introduced a new puzzle format. Adapted from a two-player paper game called Slither into a single-player pencil puzzle, Slitherlink offers a paradoxical solving pleasure — proving where lines cannot go rather than where they can — and carries a nearly 38-year lineage running through NP-completeness proofs to Steam storefronts in the 2020s. We trace, with sources, the loop-logic Nikoli founder Maki Kaji once called "the son of Sudoku."

  43. Ep. 12
    PuzzleScript (2013) — la règle d'une ligne qui a produit en masse les « jeux de poussée » du monde entier
    2026-07-20

    En octobre 2013, Stephen Lavelle (increpare) publie gratuitement PuzzleScript, un moteur de puzzle pour navigateur. Cet outil, qui permet de créer des puzzles de type Sokoban-like en une seule ligne de règle, a donné naissance, via les premières œuvres d'Alan Hazelden, à A Good Snowman Is Hard to Build, puis, en passant par ce que Hempuli lui-même appelle « la renaissance du puzzle à blocs », a nourri le terreau de Baba Is You. Cet article vérifie cette généalogie.

  44. Ep. 11
    Hanayama Cast Puzzle (1983) — Comment un seul concepteur a relié les jouets en métal aux jeux d'évasion numériques
    2026-07-19

    En 1983, le fabricant de jouets japonais Hanayama a lancé Cast Puzzle, une gamme de casse-têtes métalliques à assembler et désassembler. Nob Yoshigahara (1936-2004), qui supervisait la série, a sans le savoir relié cette expérience de casse-tête métallique sans mots à deux jalons ultérieurs : le puzzle à glissières Rush Hour (1996), et The Room de Fireproof Games (2012), dont la conception a plus tard atteint Steam. Cet article retrace une lignée de quatre décennies pour un casse-tête qui refuse encore de se refermer tout à fait.

  45. Ep. 10
    Tangram (Qi Qiao Ban) — Around 1810, Seven Pieces of Lies and Truth
    2026-07-12

    Seven shapes, five triangles, one square, one parallelogram, enough to form countless silhouettes. The tangram's origin lies in late-18th-century China, but its history was long distorted by a fabricated chronicle puzzle maker Sam Loyd wrote in 1903. I dig up both the toy's true voyage and the fiction that obscured it.

  46. Ep. 9
    Real Escape Game (2007) — de deux pièces à Kyoto à des salles d'évasion répandues dans le monde entier
    2026-07-10

    Le 7 juillet 2007, à la galerie « Inspi Bloo » à Kyoto. En guise de divertissement pour la fête du 3e anniversaire du journal gratuit « SCRAP », M. Takao Kato a réparti environ 100 personnes en 14 équipes et organisé un événement de résolution d'énigmes se déroulant dans deux pièces. C'est la première nuit, documentée, de ce que l'on appellera plus tard le « Real Escape Game », un phénomène qui grandira jusqu'à des installations commerciales dans le monde entier. M. Kato témoigne lui-même que l'élément déclencheur fut son engouement pour les jeux d'évasion du web. Je décrypte cette nuit-là comme un enregistrement rare où un puzzle contenu dans un écran a fait un pas dans l'espace réel.

  47. Ep. 8
    Henry Dudeney (1907) — Four Hinged Pieces That Turn a Triangle Into a Square
    2026-07-08

    In 1907, English puzzle maker Henry Dudeney published, within The Canterbury Puzzles, the Haberdasher's Puzzle: cutting an equilateral triangle into just four pieces that reform into a square. Hinged together, the pieces could transform with a single fold, and the dissection drew attention in its day -- yet the proof that four pieces were truly minimal remained unresolved for a surprisingly long time, settled only by a 2024 computational-geometry paper. Tracing Dudeney's rivalry with Sam Loyd and his rediscovery through Martin Gardner, this piece rereads how a paper puzzle took 117 years to reach computer science.

  48. Ep. 7
    The Birth of the Jigsaw Puzzle (1760s) — The Man Who Cut Up Maps, and a Verb Unchanged for 260 Years
    2026-07-07

    In 1760s London, the map engraver John Spilsbury mounted printed maps on wood and cut them apart along national borders, selling them as 'Dissected Maps' — the commercial starting point of what would later be called the jigsaw puzzle. This essay revisits the context in which the format was born as a tool for teaching geography, the structural insight that where you cut is itself the design, and the lineage that runs from Depression-era die-cut cardboard to the 2021 VR title Puzzling Places — a format that survived 260 years without ever changing its verb.

  49. Ep. 6
    Nikoli (1980) — The Reader-Grown Puzzle Magazine, and the Road Sudoku Took Around the World
    2026-07-02

    Puzzle Communication Nikoli, launched in 1980, was Japan's first magazine devoted to puzzles. Its name came from a racehorse; the prototype of Sudoku came from America. This essay traces forty years in which Nikoli's mode of production—reader submissions and handmade problems—gave birth to Slitherlink (1989) and Nurikabe (1991), and sent Sudoku around the world via Hong Kong judge Wayne Gould's generator program, rereading the source of a question at the heart of modern puzzle design: who should make a good problem?

  50. Ep. 5
    Professor Layton and the Curious Village (2007) - A Vessel That Carried 1966's Riddles onto a Handheld
    2026-07-01

    On February 15, 2007, Level-5 released Professor Layton and the Curious Village for the Nintendo DS. Its bundle of riddles derives directly from Akira Tago's Atama no Taisou (Kobunsha, 1966), the puzzle books producer Akihiro Hino adored as a child. This essay traces, from a historian's view, how Layton's stance of sinking a paper puzzle collection into a narrative vessel connects a forty-year-old book to a handheld, and onward to today's deduction puzzles.

  51. Ep. 4
    Les mots croisés (1913) — La lignée de la grille née du losange d'Arthur Wynne
    2026-06-30

    Le 21 décembre 1913, le « Word-Cross » d'Arthur Wynne est imprimé dans le supplément de divertissement du New York World. Rebaptisé « mots croisés » par une erreur de composition, le jeu se répand massivement grâce au livre de Simon & Schuster en 1924, puis s'internationalise via The Times en 1930 et le New York Times en 1942. Cet essai retrace comment les trois inventions — grille, croisement et indice — survivent comme vocabulaire de conception pour les puzzles de réflexion, des cases papier aux puzzles au crayon de Nikoli et aux œuvres numériques modernes.

  52. Ep. 3
    La Tour de Hanoï (1883) — Un héritage récursif inscrit dans 64 disques sans fin
    2026-06-29

    En 1883, le mathématicien français Édouard Lucas lança sous le pseudonyme « N. Claus (de Siam) » un jouet en bois. Trois tiges, des disques de tailles différentes, deux règles seulement. Mais derrière cette apparence simple se cachait la mathématique de la récursion : il faut au minimum 2ⁿ−1 mouvements pour déplacer n disques. Cet article revisite sous un angle historique la véritable origine de ce jouet, la légende de Bénarès selon laquelle le monde s'effondrerait quand la tour serait terminée, et l'héritage que les concepts de « récursion » et d'« espace d'états » ont laissé à l'informatique moderne et aux puzzles contemporains.

  53. Ep. 2
    Rubik's Cube (1974) — Un labyrinthe de 43 quintillions d'états, et une seule solution
    2026-06-25

    En 1974, l'architecte budapestois Ernő Rubik sculpte un petit cube comme outil pédagogique — et se retrouve à placer dans une main entière un « espace d'états » de quelque 43 quintillions de configurations, avec une seule forme résolue. Cet article retrace la provenance précise de l'objet à travers des sources primaires et secondaires — son invention en 1974, ses débuts mondiaux en 1980, et la preuve établie en 2010 que « le nombre de Dieu est 20 » — et lit, comme histoire, comment un objet sans écran ni alimentation électrique incarnait déjà il y a un demi-siècle le vocabulaire que les concepteurs de puzzles utilisent aujourd'hui : réversibilité, solution unique, espace à explorer.

  54. Ep. 1
    Le Taquin (1880) — Le coup insoluble dont Sam Loyd trompa le monde entier
    2026-06-16

    Au début de l'année 1880, une folie pour le « 15-puzzle » (taquin) s'empara de l'Amérique et de l'Europe. Mais Sam Loyd, que le monde croyait être l'inventeur, était un imposteur qui ne revendiqua la paternité que seize ans après la fin de la frénésie. Cet article retrace la véritable origine du jeu et la preuve de 1879 que la disposition « 14 et 15 échangés » sur laquelle Loyd misait sa récompense est mathématiquement insoluble, et relit depuis l'histoire l'héritage que les puzzles coulissants ont laissé à la conception de jeux numériques modernes : la garantie de la solubilité.