# Category: Logic puzzles

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Logic puzzle
A logic puzzle is a puzzle deriving from the mathematical field of deduction.
Mastermind (board game)
Mastermind or Master Mind is a code-breaking game for two players. It resembles an earlier pencil and paper game called Bulls and Cows that may date back a century.
Shakashaka
Shakashaka (シャカシャカ) is a logic puzzle developed by publisher Nikoli.
Gear Cube
The Gear Cube is a 3-D combination puzzle designed and created by Dutch puzzle maker Oskar van Deventer based on an idea by Bram Cohen. It was initially produced by Shapeways in 2009 and known as "Cau
Skewb
The Skewb (/ˈskjuːb/) is a combination puzzle and a mechanical puzzle in the style of the Rubik's Cube. It was invented by Tony Durham and marketed by Uwe Mèffert. Although it is cubical in shape, it
Futoshiki
Futoshiki (不等式, futōshiki), or More or Less, is a logic puzzle game from Japan. Its name means "inequality". It is also spelled hutosiki (using Kunrei-shiki romanization). Futoshiki was developed by T
LaserTank
LaserTank (also known as Laser Tank) is a computer puzzle game requiring logical thinking to solve a variety of levels. It is open source, careware, and can be used for free. The player must be able t
Hitori
Hitori (Japanese: "Alone" or "one person"; ひとりにしてくれ Hitori ni shite kure; literally "leave me alone") is a type of logic puzzle published by Nikoli. Hitori is NP complete.
Battleship (puzzle)
The Battleship puzzle (sometimes called Bimaru, Yubotu, Solitaire Battleships or Battleship Solitaire) is a logic puzzle based on the Battleship guessing game. It and its variants have appeared in sev
Self-reference puzzle
A self-reference puzzle is a type of logical puzzle where the question in the puzzle refers to the attributes of the puzzle itself.A common example is that a "fill in the blanks" style sentence is giv
Takuzu
Takuzu, also known as Binairo, is a logic puzzle involving placement of two symbols, often 1s and 0s, on a rectangular grid. The objective is to fill the grid with 1s and 0s, where there is an equal n
Goishi Hiroi
Goishi Hiroi, also known as Hiroimono, is a Japanese variant of peg solitaire. In it, pegs (or stones on a Go board) are arranged in a set pattern, and the player must pick up all the pegs or stones,
Tantrix
Tantrix is a hexagonal tile-based abstract game invented by Mike McManaway from New Zealand. Each of the 56 different tiles in the set contains three lines, going from one edge of the tile to another.
The chessboard paradox or paradox of Loyd and Schlömilch is a falsidical paradox based on an optical illusion. A chessboard or a square with a side length of 8 units is cut into four pieces. Those fou
Shinro
Shinro (しんろ) is a logic-based puzzle that has similarities to Sudoku and Minesweeper. The objective is to locate 12 hidden 'Holes' on an 8×8 grid. The board contains a variable number of arrows, each
Stained Glass (puzzle)
Masyu
Masyu (ましゅ, Mashu, IPA [maɕu͍]; translates as "evil influence") is a type of logic puzzle designed and published by Nikoli. The purpose of its creation was to present a puzzle that uses no numbers or
Train shunting puzzle
Train shunting puzzles, also often called railway shunting puzzles or railroad switching puzzles, are a type of puzzle. Shunting puzzles usually consist of a specific track layout, a set of initial co
Hashiwokakero
Hashiwokakero (橋をかけろ Hashi o kakero; lit. "build bridges!") is a type of logic puzzle published by Nikoli. It has also been published in English under the name Bridges or Chopsticks (based on a mistra
Sudoku
Sudoku (/suːˈdoʊkuː, -ˈdɒk-, sə-/; Japanese: 数独, romanized: sūdoku, lit. 'digit-single'; originally called Number Place) is a logic-based, combinatorial number-placement puzzle. In classic Sudoku, the
Heyawake
Heyawake (Japanese: へやわけ, "divided rooms") is a binary-determination logic puzzle published by Nikoli. As of 2013, five books consisting entirely of Heyawake puzzles have been published by Nikoli. It
MindTrap
MindTrap is a series of lateral thinking puzzle games played by two individuals or teams. Invented in Canada, it is the main product of , who license the game for manufacture by various companies incl
The Wason selection task (or four-card problem) is a logic puzzle devised by Peter Cathcart Wason in 1966. It is one of the most famous tasks in the study of deductive reasoning. An example of the puz
Balance puzzle
A balance puzzle or weighing puzzle is a logic puzzle about balancing items—often coins—to determine which holds a different value, by using balance scales a limited number of times. These differ from
Truel
Truel and triel are neologisms for a duel between three opponents, in which players can fire at one another in an attempt to eliminate them while surviving themselves.
KenKen
KenKen and KenDoku are trademarked names for a style of arithmetic and logic puzzle invented in 2004 by Japanese math teacher Tetsuya Miyamoto, who intended the puzzles to be an instruction-free metho
Cheryl's Birthday
"Cheryl's Birthday" is a logic puzzle, specifically a knowledge puzzle. The objective is to determine the birthday of a girl named Cheryl using a handful of clues given to her friends Albert and Berna
Atsumari
Atsumari (Japanese: 集まり; translates as "collection", "meeting", or "cluster") is a binary-determination puzzle that was originally developed by Quadratic Games for the iPhone platform. The puzzle is p
Square-1 (puzzle)
The Square-1 is a variant of the Rubik's Cube. Its distinguishing feature among the numerous Rubik's Cube variants is that it can change shape as it is twisted, due to the way it is cut, thus adding a
Slitherlink (also known as Fences, Takegaki, Loop the Loop, Loopy, Ouroboros, Suriza and Dotty Dilemma) is a logic puzzle developed by publisher Nikoli.
Lights Out (game)
Lights Out is an electronic game released by Tiger Electronics in 1995. The game consists of a 5 by 5 grid of lights. When the game starts, a random number or a stored pattern of these lights is switc
Rope-burning puzzle
In recreational mathematics, rope-burning puzzles are a class of mathematical puzzle in which one is given lengths of rope, fuse cord, or shoelace that each burn for a given amount of time, and matche
Fill-In (puzzle)
Fill-Ins, also known as Fill-It-Ins or Word Fill-Ins, are a variation of the common crossword puzzle in which words, rather than clues, are given, and the solver must work out where to place them. Fil
Fillomino
Fillomino (フィルオミノ) is a type of logic puzzle published by many publishers. Other published titles for the puzzle include Allied Occupation.
THOG problem
The THOG problem is one of cognitive psychologist Peter Wason's logic puzzles, constructed to show some of the weaknesses in human thinking. You are shown four symbols 1. * a black square 2. * a whi
Jeep problem
The jeep problem, desert crossing problem or exploration problem is a mathematics problem in which a jeep must maximize the distance it can travel into a desert with a given quantity of fuel. The jeep
Bulls and Cows
Bulls and Cows (also known as Cows and Bulls or Pigs and Bulls) is a code-breaking mind or paper and pencil game for two or more players, predating the commercially marketed board game Mastermind and
Survo puzzle
A Survo puzzle is a kind of logic puzzle presented (in April 2006) and studied by .The name of the puzzle is associated with Mustonen's , which is a general environment for statistical computing and r
God's algorithm
God's algorithm is a notion originating in discussions of ways to solve the Rubik's Cube puzzle, but which can also be applied to other combinatorial puzzles and mathematical games. It refers to any a
Wolf, goat and cabbage problem
The wolf, goat and cabbage problem is a river crossing puzzle. It dates back to at least the 9th century, and has entered the folklore of several cultures.
Shikaku
Shikaku (四角に切れ, shikaku ni kire) (also anglicised as Divide by Squares or Divide by Box) is a logic puzzle published by Nikoli. As of 2011, two books consisting entirely of Shikaku puzzles has been pu
Monkey and banana problem
The monkey and banana problem is a famous toy problem in artificial intelligence, particularly in logic programming and planning.
Petals Around the Rose
Petals Around the Rose is a mathematically challenging puzzle in which the object is to work out the formula by which a number is derived from the roll of a set of five or six dice. It is often used a
Sum and Product Puzzle
The Sum and Product Puzzle, also known as the Impossible Puzzle because it seems to lack sufficient information for a solution, is a logic puzzle. It was first published in 1969 by Hans Freudenthal, a
Keisuke (puzzle)
On the Trail of the Golden Owl
On The Trail Of The Golden Owl (French: Sur la trace de la chouette d'or) is a French armchair treasure hunt book created by communications expert Régis Hauser under the pseudonym "Max Valentin" and i
Bridge and torch problem
The bridge and torch problem (also known as The Midnight Train and Dangerous crossing) is a logic puzzle that deals with four people, a bridge and a torch. It is in the category of river crossing puzz
MU puzzle
The MU puzzle is a puzzle stated by Douglas Hofstadter and found in Gödel, Escher, Bach involving a simple formal system called "MIU". Hofstadter's motivation is to contrast reasoning within a formal
Zebra Puzzle
The zebra puzzle is a well-known logic puzzle. Many versions of the puzzle exist, including a version published in Life International magazine on December 17, 1962. The March 25, 1963, issue of Life c
Mutilated chessboard problem
The mutilated chessboard problem is a tiling puzzle posed by Max Black in 1946 that asks: Suppose a standard 8×8 chessboard (or checkerboard) has two diagonally opposite corners removed, leaving 62 sq
Yajilin
Yajilin (ヤジリン) is a type of logic puzzle published by Nikoli. It has been published in English under the name Arrow Ring, such as in the 2005 U.S. qualifier for the World Puzzle Championship.
Bag (puzzle)
Bag (also called Corral or Cave) is a binary-determination logic puzzle published by Nikoli.
Dissection puzzle
A dissection puzzle, also called a transformation puzzle or Richter Puzzle, is a tiling puzzle where a set of pieces can be assembled in different ways to produce two or more distinct geometric shapes
Light Up (puzzle)
Light Up (Japanese: 美術館 bijutsukan, art gallery), also called Akari, is a binary-determination logic puzzle published by Nikoli. As of 2011, three books consisting entirely of Light Up puzzles have be
Nikoli (publisher)
Nikoli Co., Ltd. (Japanese: 株式会社ニコリ, Hepburn: Kabushiki-gaisha, Nikori) is a Japanese publisher that specializes in games and, especially, logic puzzles. Nikoli is also the nickname of a quarterly mag
The Hardest Logic Puzzle Ever
The Hardest Logic Puzzle Ever is a logic puzzle so called by American philosopher and logician George Boolos and published in The Harvard Review of Philosophy in 1996. Boolos' article includes multipl
Kuromasu
Where are the black cells? (Japanese: 黒枡（くろマス）はどこだ？, Hepburn: Kuromasu wa doko da?), abbreviated Kuromasu (黒（くろ）マス) or Kurodoko (黒（くろ）どこ), is a binary-determination logic puzzle published by Nikoli. A
Hotaru Beam
Hotaru Beam (lit. 'firefly beam') is a binary-determination logic puzzle published by Nikoli.
Nurikabe (puzzle)
Nurikabe (hiragana: ぬりかべ) is a binary determination puzzle named for Nurikabe, an invisible wall in Japanese folklore that blocks roads and delays foot travel. Nurikabe was apparently invented and nam
Numberlink is a type of logic puzzle involving finding paths to connect numbers in a grid.
Buchstabensalat (logic puzzle)
Buchstabensalat, commonly referred to as "End View" or "Easy as ABC" or "ABC End View", is a logic puzzle. A Buchstabensalat puzzle consists of a set of letters or "alphabet" (for instance, "A-E") and
Hooper's paradox is a falsidical paradox based on an optical illusion. A geometric shape with an area of 32 units is dissected into four parts, which afterwards get assembled into a rectangle with an
Four glasses puzzle
The four glasses puzzle, also known as the blind bartender's problem, is a logic puzzle first publicised by Martin Gardner in his "Mathematical Games" column in the February 1979 edition of Scientific
Theseus and the Minotaur
Theseus and the Minotaur is a type of logic maze designed by Robert Abbott. In this maze, the player acts as Theseus, the king of Athens who is attempting to escape the Labyrinth. The main difference
Tentai Show
Tentai Show (Japanese: 天体ショー tentai shō), also known by the names Tentaisho, Galaxies, Spiral Galaxies, or Sym-a-Pix, is a binary-determination logic puzzle published by Nikoli.
Missionaries and cannibals problem
The missionaries and cannibals problem, and the closely related jealous husbands problem, are classic river-crossing logic puzzles. The missionaries and cannibals problem is a well-known toy problem i
Hidato
Hidato (Hebrew: חידאתו, originating from the Hebrew word Hida = Riddle), also known as "Hidoku", is a logic puzzle game invented by Dr. Gyora M. Benedek, an Israeli mathematician. The goal of Hidato i
Logic maze
Logic mazes, sometimes called mazes with rules or multi-state mazes, are logic puzzles with all the aspects of a tour puzzle that fall outside of the scope of a typical maze. These mazes have special
Induction puzzles
Induction puzzles are logic puzzles, which are examples of multi-agent reasoning, where the solution evolves along with the principle of induction. A puzzle's scenario always involves multiple players
Missing dollar riddle
The missing dollar riddle is a famous riddle that involves an informal fallacy. It dates to at least the 1930s, although similar puzzles are much older.
Escape room
An escape room, also known as an escape game, puzzle room, exit game, or riddle room is a game in which a team of players discover clues, solve puzzles, and accomplish tasks in one or more rooms in or
Missing square puzzle
The missing square puzzle is an optical illusion used in mathematics classes to help students reason about geometrical figures; or rather to teach them not to reason using figures, but to use only tex
Wine/water mixing problem
In the wine/water mixing problem, one starts with two barrels, one holding wine and the other an equal volume of water. A cup of wine is taken from the wine barrel and added to the water. A cup of the
River crossing puzzle
A river crossing puzzle is a type of puzzle in which the object is to carry items from one river bank to another, usually in the fewest trips. The difficulty of the puzzle may arise from restrictions
Verbal arithmetic
Verbal arithmetic, also known as alphametics, cryptarithmetic, cryptarithm or word addition, is a type of mathematical game consisting of a mathematical equation among unknown numbers, whose digits ar
Ripple Effect (puzzle)
Ripple Effect (Japanese:波及効果 Hakyuu Kouka) is a logic puzzle published by Nikoli. As of 2007, two books consisting entirely of Ripple Effect puzzles have been published by Nikoli. The second was publi
Water pouring puzzle
Water pouring puzzles (also called water jug problems, decanting problems, measuring puzzles, or Die Hard with a Vengeance puzzles) are a class of puzzle involving a finite collection of water jugs of
Tatamibari
Tatamibari (Japanese: タタミバリ) is a type of logic puzzle designed and published by Nikoli. The puzzle is based on Japanese tatami mats.
Str8ts
Str8ts is a logic-based number-placement puzzle, invented by Jeff Widderich in 2008. It is distinct from, but shares some properties and rules with Sudoku. The name is derived from the poker straight.
Rubik's Cube
The Rubik's Cube is a 3-D combination puzzle originally invented in 1974 by Hungarian sculptor and professor of architecture Ernő Rubik. Originally called the Magic Cube, the puzzle was licensed by Ru
Coercive logic
Coercive logic is a concept popularised by mathematician Raymond Smullyan, by which a person who has agreed to answer a question truthfully is forced to perform an undesired action, where not doing so
Helicopter Cube
The Helicopter Cube is a Rubik's Cube-like puzzle invented by Adam G. Cowan in 2005 and built in 2006. It is also in the shape of a cube. At first glance, the Helicopter Cube may seem like a combinati
Ages of Three Children puzzle
The Ages of Three Children puzzle is a logic puzzle which on first inspection seems to have insufficient information to solve, but which rewards those who persist and examine the puzzle critically.
Kakuro
Kakuro or Kakkuro or Kakoro (Japanese: カックロ) is a kind of logic puzzle that is often referred to as a mathematical transliteration of the crossword. Kakuro puzzles are regular features in many math-an
Super Swap
Super Swap is an action puzzle game developed by Teyon for the Nintendo DSiWare. It is available in the Nintendo DSi Shop for 500 Nintendo DSi Points.
Knights and Knaves
Knights and Knaves is a type of logic puzzle where some characters can only answer questions truthfully, and others only falsely. The name was coined by Raymond Smullyan in his 1978 work What Is the N
Sokoban
Sokoban (倉庫番, Sōko-ban, lit. 'warehouse keeper') is a puzzle video game subgenre in which the player pushes crates or boxes around in a warehouse, trying to get them to storage locations. The game was
Sujiko
Sujiko is a logic-based, combinatorial number-placement puzzle created by Jai Gomer of Kobayaashi Studios. The puzzle takes place on a 3x3 grid with four circled number clues at the centre of each qua
Cross-figure
A cross-figure (also variously called cross number puzzle or figure logic) is a puzzle similar to a crossword in structure, but with entries that consist of numbers rather than words, where individual
LITS
LITS, formerly known as Nuruomino (ヌルオミノ), is a binary determination puzzle published by Nikoli.
Nonogram
Nonograms, also known as Hanjie, Paint by Numbers, Picross, Griddlers, and Pic-a-Pix, and by various other names, are picture logic puzzles in which cells in a grid must be colored or left blank accor
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