The Sudoku Cube or Sudokube is a variation on a Rubik's Cube in which the aim is to solve one or more Sudoku puzzles on the sides or rows. The toy was originally created in 2006 by Jay Horowitz in Sebring, Ohio, [1] and has since been the inspiration for several similar products and variations.
The Sudoku Cube was invented by veteran toy maker Jay Horowitz. Horowitz first encountered the original Sudoku puzzle when a woman sitting next to him on a plane ride explained it to him. On the same plane ride, Horowitz had the idea of combining it with the Rubik's cube. [2] [3] [4] He worked for a month with help from toy buyer Ken Moe until he figured out how to combine them together, and then when he figured it out, he "did not sleep for three days" while he worked out how to best arrange the numbers to create 18 unique Sudoku puzzles within the cube. [2] [3] [4] Horowitz already owned molds to produce Rubik's Cubes, as he owned the Ideal Toy Company which had produced them in the past and he was able to use them to produce his new design. [2] Horowitz then patented the numerical design that he created. [4] Mass production was completed in China by American Classic Toy Inc, a company belonging to Horowitz. The product was sold in the United States in retailers such as Barnes & Noble and FAO Schwarz and sold for $9.87 each (a price chosen because each number appears once). [4] [2]
Horowitz promoted his new product online, [5] [6] [7] [8] [9] [10] [11] [12] in magazines, [13] [14] [4] in newspapers, [1] [2] [15] [16] [17] [18] [19] [20] [21] and at toy fairs such as the 2007 American International Toy Fair and Hong Kong Toys and Games Fair, [2] [22] and on TV with English and Spanish commercials and demo videos. [23] [24] [25] [26] [27] Adrienne Citrin, the spokeswoman for the Toy Industry Association, mentioned that Sudoku fans who felt like they had mastered the original paper version of the puzzle were interested in the new product. [2] The product was originally launched in the US and then sold internationally, exporting to Spain, France, South Africa and the United Kingdom. [22] Shortly after release, there were several imitator products sold on Amazon under the name "Sudokube". [2] [28]
In a standard Rubik's Cube, the player must match up colors on each side of the cube. In the standard Sudoku, the player has to fill the grid with the digits 1-9 such that no digit is repeated in any of the rows, columns or squares. In the original Sudoku Cube, the player has several different objectives, some of which are borrowed from the original Sudoku puzzle, and one of which is borrowed from the original Rubik's Cube. The Sudoku objectives are mostly organized from levels 1-9, and are categorized into beginner (levels 1-3), intermediate (levels 4-6), advanced (levels 7-8) and master (level 9): [29] [30]
Levels 1-3 all involve solving a number of sides. A side is considered solved when it contains each one of the digits 1-9 in the correct orientation:
The intermediate levels are similar to the beginner levels, but involve solving more sides:
The advanced levels also include solving vertical columns and horizontal rows. A vertical column is considered complete when the digits 1-9 are in a vertical column on three contiguous sides of the cube. Likewise, the horizontal row is considered complete when the digits 1-9 are in a horizontal row on three contiguous sides of the cube:
The master level involves solving all 18 Sudoku in the cube:
In addition to the objectives derived from the Sudoku puzzle that use the numbers inscribed onto each sticker of the cube, the stickers are also colored such that the puzzle can also be solved like an original Rubik's Cube.
A Sudoku Cube key chain version was released, which was smaller and cheaper - selling for $3.97 + $3.49 shipping. [31]
Following the success of the Sudoku Cube, Horowitz created two more Sudoku products: The Sudoku Slide and The Sudoku Solitaire.
A colorless Sudoku cube removes the different colors from the cube, meaning the only objective is to place the digits 1-9 on each side, in the correct orientation. [32] [33] [34]
A numberless Sudoku cube removes the numbers entirely and uses colors to form the Sudoku challenge. The cube contains nine different colors, and the objective is to place one of each color on each side. [35]
2×2×2 and 4×4×4 Sudoku cubes have also been created and mass produced, also with various colorless and numberless variations. [36] [37] [38]
The molecube is a further variation on the numberless Sudoku Cube created by Uwe Mèffert, which has spherical pieces. [39]
V-Cube created a variation which contains nine digits on each sticker, meaning that each side contains eighty-one digits in a 9×9 configuration. The goal of this puzzle is to complete a traditional 9×9 Sudoku on each side. [40] [41]
There are several techniques used to solve the Sudoku Cube and its variations.
A technique common to all Sudoku Cubes is to split the problem into finding the configuration of the pieces, and the mechanics of solving the cube. It is assumed that the solver already understands the mechanics of solving the cube, and therefore the problem is reduced into finding the configuration of the pieces. [42]
A common technique for finding the configuration of the pieces it to map the three dimensional Sudoku Cube onto a two dimensional net. This allows for easier visualization of the pieces, and makes it easier to see the constraints that hold each piece in a separate position. [43]
The corners first approach involves solving the corners of the 3×3×3 Sudoku Cube like a 2×2×2 Sudoku Cube. This is an easier problem to solve, but makes solving the edges of the cube significantly easier. [44]
The requirement for the numbers on the Sudoku Cube to be oriented the same direction as the other numbers on the side significantly restricts which pieces are able to border each other. This allows for deductive reasoning which can be used to find which pieces must border each other, and hence how the cube must be solved. [45]
3-D programming languages such as VPython can be used to create simulations of a Sudoku Cube. [46] Such simulations can offer features such as scaling the Sudoku Cube (to create 4×4×4 or 5×5×5 puzzles), saving, resetting, undoing, and the option to design one's own Sudoku Cube patterns.
The Rubik's Cube is a 3D combination puzzle invented in 1974 by Hungarian sculptor and professor of architecture Ernő Rubik. Originally called the Magic Cube, the puzzle was licensed by Rubik to be sold by Pentangle Puzzles in the UK in 1978, and then by Ideal Toy Corp in 1980 via businessman Tibor Laczi and Seven Towns founder Tom Kremer. The cube was released internationally in 1980 and became one of the most recognized icons in popular culture. It won the 1980 German Game of the Year special award for Best Puzzle. As of January 2024, around 500 million cubes had been sold worldwide, making it the world's bestselling puzzle game and bestselling toy. The Rubik's Cube was inducted into the US National Toy Hall of Fame in 2014.
A puzzle is a game, problem, or toy that tests a person's ingenuity or knowledge. In a puzzle, the solver is expected to put pieces together in a logical way, in order to achieve the correct solution of the puzzle. There are different genres of puzzles, such as crossword puzzles, word-search puzzles, number puzzles, relational puzzles, and logic puzzles. The academic study of puzzles is called enigmatology.
The Rubik's Revenge is a 4×4×4 version of the Rubik's Cube. It was released in 1981. Invented by Péter Sebestény, the cube was nearly called the Sebestény Cube until a somewhat last-minute decision changed the puzzle's name to attract fans of the original Rubik's Cube. Unlike the original puzzle, it has no fixed faces: the center faces are free to move to different positions.
Rubik's Magic, like the Rubik's Cube, is a mechanical puzzle invented by Ernő Rubik and first manufactured by Matchbox in the mid-1980s.
Speedcubing, also referred to as speedsolving, is a competitive sport centered around the rapid solving of various combination puzzles. The most prominent puzzle in this category is the 3x3x3 puzzle, commonly known as the Rubik's Cube. Participants in this sport are known as "speedcubers," who focus specifically on solving these puzzles at high speeds, or more generally as "cubers". The essential aspect of solving these puzzles typically involves executing a series of predefined algorithms in a particular sequence.
The Professor's Cube is a 5×5×5 version of the original Rubik's Cube. It has qualities in common with both the 3×3×3 Rubik's Cube and the 4×4×4 Rubik's Revenge, and solution strategies for both can be applied.
The Pyraminx is a regular tetrahedron puzzle in the style of Rubik's Cube. It was made and patented by Uwe Mèffert after the original 3 layered Rubik's Cube by Ernő Rubik, and introduced by Tomy Toys of Japan in 1981.
Sudoku is a logic-based, combinatorial number-placement puzzle. In classic Sudoku, the objective is to fill a 9 × 9 grid with digits so that each column, each row, and each of the nine 3 × 3 subgrids that compose the grid contains all of the digits from 1 to 9. The puzzle setter provides a partially completed grid, which for a well-posed puzzle has a single solution.
Mathematics can be used to study Sudoku puzzles to answer questions such as "How many filled Sudoku grids are there?", "What is the minimal number of clues in a valid puzzle?" and "In what ways can Sudoku grids be symmetric?" through the use of combinatorics and group theory.
This is a glossary of Sudoku terms and jargon. Sudoku with a 9×9 grid is assumed, unless otherwise noted.
Uwe Mèffert was a German puzzle designer and inventor. He manufactured and sold mechanical puzzles in the style of Rubik's Cube since the Cube craze of the 1980s. His first design was the Pyraminx – which he had developed before the original Rubik's Cube was invented. He created his own puzzle company and helped bring to market the Megaminx, Skewb, Skewb Diamond and many other puzzles.
The Rubik's Revolution is a handheld electronic game invented, designed, developed and patented by Rehco, LLC, a Chicago toy and game inventing firm. The Rubik's Revolution was formerly distributed by Techno Source and received the 2008 TOTY Game of the Year Award. 11-12 years later, it would be revamped by Techno Source's parent company, Super Impulse and be regarded as one of the many toys that would help battle boredom in the Covid-19 Pandemic according to Time To Play Mag Designed to resemble the classic Rubik's Cube puzzle, the device is a single rigid cube; it is about as large as a Professor's Cube, with each face subdivided into 9 square sub-faces. The center square of each face features a recessed LED-lit button colored to correspond with the stickers on the remaining squares. Gameplay involves pressing the buttons when they light up, or when directed to by the game's recorded voice.
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 method of training the brain. The name derives from the Japanese word for cleverness. The names Calcudoku and Mathdoku are sometimes used by those who do not have the rights to use the KenKen or KenDoku trademarks.
The V-Cube 7 is a combination puzzle in the form of a 7×7×7 cube. The first mass-produced 7×7×7 was invented by Panagiotis Verdes and is produced by the Greek company Verdes Innovations SA. Other such puzzles have since been introduced by a number of Chinese companies, some of which have mechanisms which improve on the original. Like the 5×5×5, the V-Cube 7 has both fixed and movable center facets.
The Rubik's Triamid is a mechanical puzzle invented by Ernő Rubik and released in 1990 by Matchbox. The puzzle was patented in Hungary in 1991. It was re-released in 2017 at the American International Toy Fair by Winning Moves.
RuBot II is a Rubik's Cube solving robot developed by Irish roboticist and inventor Pete Redmond. RuBot II is also known as RuBot II, the Cubinator. RuBot II became the world's fastest Rubik's Cube-solving robot, and appeared as such in the Guinness Book of World Records. There are other Rubik's Cube robots too.
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. The puzzle is published in a number of newspapers internationally, in two book collections, and in downloadable apps. It was featured on the Canadian television show Dragons' Den on November 24, 2010.
Tony Fisher is a British puzzle designer who specialises in creating custom rotational puzzles. He is acknowledged by cubing enthusiasts as a pioneer in the creation of new puzzle designs and new manufacturing techniques. In 2017 the Guinness Book of World Records acknowledged Fisher as the creator of the world's largest Rubik's cube.
The Nine-Colour Cube is a cubic twisty puzzle. It was invented in 2005 by Milan Vodicka and mass-produced by Meffert's seven years later. Mechanically, the puzzle is identical to the Rubik's Cube; however, unlike the 3×3×3 Rubik's Cube, which only has 6 different colours, the Nine-Colour Cube has 9 colours, with the individual pieces having one colour each.
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 "Caution Cube" due to the likelihood of getting one's fingers stuck between the gears while speedcubing. Later, in 2010, it was mass-produced by Meffert's as the "Gear Cube".