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.
Episodes
- Ep. 54Game of Life (1970) — A Grid with Two Rules Gained the Power to Compute2026-10-07
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.
- Ep. 53Hexaflexagon (1939) — Paper Scraps Trimmed from a Notebook Grew a Hidden Face2026-10-06
In 1939 Princeton graduate student Arthur Stone folded trimmed paper strips and found a hexagon whose faces swap. Feynman and Tukey were among his colleagues. Martin Gardner introduced it in December 1956, and it became widely known. We trace its history within what the sources confirm.
- Ep. 52Knight's Tour (c. 840) — How Chess Without the Contest Became Poetry and Mathematics2026-10-05
The puzzle of visiting all 64 squares with a knight's jump goes back to ninth-century manuscripts and Indian poetry. Euler treated it in 1759, Warnsdorff gave a rule in 1823, and the count was confirmed in 1997. This traces its history from the sources I could check.
- Ep. 51Tower of Hanoi (1883) — The 64-Disk Legend a Mathematician Sold Under a Pseudonym2026-10-04
In 1883 the French mathematician Lucas sold a three-peg disk puzzle under the name "Professor N. Claus (de Siam)". The minimum for n disks is 2^n − 1 moves; the legendary 64 disks would take about 585 billion years. Bousch showed in 2014 that the four-peg count is optimal. This traces its history from the sources I could check.
- Ep. 50Eight Queens (1848) — Eight Pieces, None Attacking: The Board Gauss Also Counted2026-10-03
In 1848 the chess problemist Max Bezzel asked for eight queens on an 8x8 board with none attacking another. Nauck gave 92 solutions in 1850 and Gauss worked on it in letters. In 1971 Dijkstra used it to teach backtracking. This article traces the one-line problem's history as far as sources could be confirmed.
- Ep. 49Sprouts (1967) — A Two-Player Game of Dots and Lines on Paper That Resists Solving2026-10-02
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.
- Ep. 48Nim (1901) — The First Stone-Taking Game to Be Solved, and the Machines That Played It2026-10-01
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.
- Ep. 47Hex (1942) — The Year a Hexagon in the Corner of a Newspaper Ruled Out a Draw2026-09-29
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.
- Ep. 46Instant Insanity (1967) — One Right Answer Among 41,4722026-09-25
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.
- Ep. 45Sangaku (1683) — Votive Tablets Hung at Shrines Not to Thank the Gods for a Solved Problem, but to Challenge the Next Visitor to Solve One2026-09-24
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.
- Ep. 44Rush Hour (1996) — The Year a Wooden Traffic Jam Earned a PSPACE-Complete Proof2026-09-23
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.
- Ep. 43Eternity Puzzle (1999) — The Year a £1 Million "Unsolvable" Fell in Seven Months2026-09-22
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.
- Ep. 42Othello (1973) — The Year a Game Whose Patent Was Rejected Was Proven, Half a Century Later, to End in a Draw2026-09-21
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.
- Ep. 41Pyraminx (1981) — Designed Before the Rubik's Cube, Released to Ride Its Boom2026-09-19
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.
- Ep. 40Nine 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 Idea2026-09-18
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.
- Ep. 39The Seven Bridges of Königsberg (1736) — The Year Euler Erased the Map to Solve a Sunday Puzzle2026-09-17
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.
- Ep. 38Peg 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.
- Ep. 37Hitori (1990) — Why a Puzzle Too Hard to Catch On for 8 Years Is Still an AI Test Case in 20252026-09-15
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.
- Ep. 36Mastermind (1970) — A Telecoms Engineer's Four Colors, Later Reborn as Fallout's Hacking Screen2026-09-14
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.
- Ep. 35The Decagon House Murders (1987) — The Debut That Answered Knox's Decalogue2026-09-12
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.
- Ep. 34SameGame (1985) — The Grammar of Clearing Same-Colored Clusters, Born From a Reader Submission2026-09-10
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.
- Ep. 33Himitsu-bako (1894) — The Souvenir That Never Explains How to Open It2026-09-09
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.
- Ep. 32Pigs in Clover (1889) — A Tilting Wooden Box That Stalled the U.S. Senate for a Season2026-09-08
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.
- Ep. 31Eggerland (1985) — The Original One-Room Puzzle Where You Push Your Enemies as Eggs2026-09-06
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.
- Ep. 30Shanghai (1986) — The Rules a Hospital PLATO Terminal Wrote2026-08-26
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.
- Ep. 29Book of Lenses (2008) — A Hundred Ways to Look at a Game2026-08-25
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.
- Ep. 28The MDA Framework (2004) — Three Words Puzzle Designers Still Use2026-08-23
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.
- Ep. 27Sudoku (1979) — How a Nameless Invention Conquered the World's Morning Papers2026-08-22
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.
- Ep. 26The Art of Computer Game Design (1984) — The First Book That Tried to Define What a Game Is2026-08-21
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.
- Ep. 25Hakoiri Musume / Klotski (1930s) — The Lineage of Blocks That Trapped Cao Cao2026-08-19
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.
- Ep. 24Hashiwokakero (1990) — Thirty-Six Years of Logic Grown from Numbers Joined by Lines2026-08-18
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.
- Ep. 23Minesweeper (1990) — The Logic Puzzle Microsoft Built Into a Billion PCs2026-08-17
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.
- Ep. 22Mirror Isles / Skipping Stones to Lonely Homes (2014-2015) — How Two Free Jam Games Became Two Different Escape Islands, a Decade Later2026-08-06
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.
- Ep. 21Nurikabe (1991) — A Ban on Two-by-Two, Borrowed from a Yōkai's Name2026-08-05
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.
- Ep. 20Masyu (2000) — The Loop of Black and White Pearls Born from a Misreading2026-08-03
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.
- Ep. 19Soma Cube (1933) — Twenty-Seven Fragments Born in a Quantum Mechanics Lecture2026-08-02
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.
- Ep. 18Get Off the Earth (1896) — The Patent Sam Loyd Took Out on a Miscount2026-07-31
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.
- Ep. 17Numberlink (1897) — From a Newspaper Puzzle Column to the Age of Flow Free and Zip2026-07-30
In 1897, puzzle-maker Sam Loyd printed 'The Puzzled Neighbors' in the Brooklyn Daily Eagle. In 1917, Henry Ernest Dudeney refined it into a motorist's puzzle in his own book; in the 1980s, Nikoli gave it a home in Japan as Arukone and Numberlink. In 2012, Big Duck Games' Flow Free turned it into colored dots and pipes and passed 100 million downloads; by 2025, the lineage reaches LinkedIn's daily puzzle Zip. This essay traces how a 120-plus-year-old rule — draw a single line without crossing — has survived.
- Ep. 16Pentomino (1965) — How Solomon Golomb's Five-Square Shape Became Tetris2026-07-29
In 1965, American mathematician Solomon W. Golomb published Polyominoes, a book that gathered the theory of the twelve five-square shapes known as pentominoes. The naming traces back to a 1953 Harvard lecture; Martin Gardner's column carried it to general readers in 1957; a Russian translation appeared in 1975. Then in 1984, a young Moscow computer scientist named Alexey Pajitnov, drawing on his own childhood memories of pentominoes, moved shapes on an experimental computer, and Tetris was born. This piece traces the more than thirty years it took a five-square shape to travel the world.
- Ep. 15Yajilin (1999) — A Board Where Two Rule-Systems Were Grafted Together2026-07-28
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.
- Ep. 14Kakuro (1966) — From Cross Sums to Addition Cross, Sixty Years of an Unmoved Grid2026-07-25
Kakuro, known in English as Cross Sums, began in 1966 as a Dell Magazines feature. Nikoli brought it to Japan in the 1980s and renamed it 'kasan kurosu' (addition cross); in 2005 it was re-exported to the world via The Guardian. This essay traces why this grid of arithmetic — neither crossword nor Sudoku, but a hybrid of both — kept its rule unchanged across sixty years of shifting media, from paper magazines to a Nintendo DS cartridge to today's Steam store pages.
- Ep. 13Slitherlink (1989) — Loop-Closing Logic Born From a Two-Player Paper Game2026-07-23
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."
- Ep. 12PuzzleScript (2013) — The One-Line Rule That Mass-Produced the World's “Pushing Games”2026-07-20
In October 2013, indie developer Stephen Lavelle (increpare) released PuzzleScript, a free browser-based puzzle engine whose Sokoban-style push rule fits on a single line of code. Traced forward, it runs through Alan Hazelden's early jam games into A Good Snowman Is Hard to Build, and — by Hempuli's own account — into the block-pushing puzzle revival that fed Baba Is You. Here the lineage is checked against the record.
- Ep. 11Hanayama Cast Puzzle (1983) — How One Designer Linked Metal Toys to Digital Escape Games2026-07-19
In 1983, Japanese toy maker Hanayama released Cast Puzzle, a line of metal disassembly puzzles. Nob Yoshigahara (1936-2004), who oversaw the series, unknowingly bridged this wordless metal-puzzle experience to two later landmarks: the 1996 sliding-block puzzle Rush Hour, and Fireproof Games' The Room (2012), whose puzzle-box design later reached Steam. This piece traces a four-decade lineage of a puzzle that still refuses to fully close.
- Ep. 10Tangram (Qi Qiao Ban) — Around 1810, Seven Pieces of Lies and Truth2026-07-12
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.
- Ep. 9The Real Escape Game (2007) — Two Rooms in Kyoto That Grew Into a Worldwide Locked Room2026-07-10
On July 7, 2007, at the Inspiblo gallery in Kyoto, Takao Kato split roughly 100 guests into 14 teams across two rooms as entertainment for the third-anniversary party of his free paper SCRAP. That night became the first installment of what would be called the 'Real Escape Game' — a phenomenon that grew into a worldwide commercial industry. Kato has testified himself that the spark was watching a staffer get hooked on web escape games. I read this night as a rare documented case of a puzzle walking out of the screen and into physical space.
- Ep. 8Henry Dudeney (1907) — Four Hinged Pieces That Turn a Triangle Into a Square2026-07-08
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.
- Ep. 7The Birth of the Jigsaw Puzzle (1760s) — The Man Who Cut Up Maps, and a Verb Unchanged for 260 Years2026-07-07
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.
- Ep. 6Nikoli (1980) — The Reader-Grown Puzzle Magazine, and the Road Sudoku Took Around the World2026-07-02
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?
- Ep. 5Professor Layton and the Curious Village (2007) - A Vessel That Carried 1966's Riddles onto a Handheld2026-07-01
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.
- Ep. 4The Crossword (1913) — The Grid Lineage That Began with Arthur Wynne's Diamond2026-06-30
On December 21, 1913, Arthur Wynne's "Word-Cross" was printed in the entertainment supplement of The New York World. Renamed "crossword" by a typesetting error, the pastime spread explosively through Simon & Schuster's 1924 book and went global via The Times in 1930 and The New York Times in 1942. This essay traces how the three inventions of grid, crossing and clue still live as a design vocabulary for thinking puzzles, from paper cells to Nikoli's pencil puzzles and modern digital works.
- Ep. 3Tower of Hanoi (1883) — The 64 Disks That Never End, and the Legacy of Recursion2026-06-29
In 1883 the French mathematician Édouard Lucas released a small wooden toy under the pseudonym 'N. Claus (de Siam).' Three pegs, disks of differing size, and just two rules. Yet beneath that plain surface lay the mathematics of recursion: moving n disks demands a minimum of 2^n−1 moves. This essay revisits the toy's true origin, the fabricated Benares legend in which the world ends when 64 disks are moved, and what the ideas of 'recursion' and 'state space' bequeathed to later computer science and to puzzle design today.
- Ep. 2Rubik's Cube (1974) — A Labyrinth of 43 Quintillion States, and a Single Solution2026-06-25
In 1974, the Budapest architect Ernő Rubik carved a small cube as a teaching aid—and ended up placing an entire 'state space,' some 43 quintillion configurations with exactly one solved form, into the palm of a hand. This piece traces the object's precise provenance through primary and secondary sources—its 1974 invention, its 1980 global debut, and the 2010 proof that 'God's Number is 20'—and reads, as history, how an object with no screen and no power supply embodied half a century early the vocabulary modern puzzle designers now take for granted: reversibility, a unique solution, and a space to be searched.
- Ep. 1The 15 Puzzle (1880) — The Unsolvable Move with Which Sam Loyd Fooled the World2026-06-16
In early 1880 a craze for the '15 Puzzle' swept America and Europe. But Sam Loyd, whom the world believed to be its inventor, was an impostor who only claimed authorship sixteen years after the craze had ended. This essay traces the box's true origin and the 1879 proof that the 'swapped 14-and-15' board Loyd staked his prize on is mathematically unsolvable, and rereads the legacy sliding puzzles left to modern digital puzzle design: the guarantee of solvability.