Sudoku is originally called Number Place. It is a puzzle-based number placement combination game. In classic sudoku, the goal is to fill a 9 x 9 grid with numbers so that each row and each column of the nine 3 x 3 sub-grids make up the whole grid, also known as regions, blocks, or boxes. These boxes contain numbers from 1 to 9. The creator of the puzzle provides a partially complete grid, which for a well-posed puzzle has only one solution.
Variants of Sudoku puzzles were features in French newspapers in the 19th century. Since 1979, the puzzle has appeared in puzzle books under the name Number Place. It was until 1986 since the modern Sudoku did not gain popularity when it was released by the Japanese puzzle company name Nikoli. They released it under the name Sudoku. All the credit goes to Wayne Gould, who designed a computer program to produce unique puzzles.
History of Sudoku
Sudoku is an easy-to-learn logic-based number-placement puzzle. The word Sudoku is the abbreviation of Su-ji wa dokushin ni kagiru, which means the number must be simple or single. The roots of the Sudoku are in Switzerland. In the 18th century, Leonhard Euler created the Latin square which was similar to the Sudoku puzzle. It was without the additional restriction on the content of individual regions.
Number puzzles first appeared in the newspaper in the late 1800s. It was the time when French puzzle makers began experimenting with removing numbers from the magic squares. Le Siècle, a Parisian daily newspaper publishes a 9 x 9 magic square partially complete with 3 x 3 sub-squares in 1892.
It was not Sudoku because it contained two-digit numbers and it required arithmetic instead of logical solutions. On the other hand, it shared the common characteristics such as column, row, and sub-square added the same number.
On July 6, 1896, Le Siecle’s rival, La France refined the puzzle into almost a modern Sudoku puzzle. It was known as a diabolical magic square or evil magic square. He simplified the 9 x 9 magic square puzzle so that each broken, row, column, and diagonal only contained the numbers 1 through 9. But he did not mark the sub-squares. Although they were not marked, each 3 x 3 sub-square contained the number 1 to 9.
The first real Sudoku game was released in 1979. It was invented by Howard Garns, who was an American architect. Real worldwide popularity began in Japan in 1986 after Nikoli released it and gave it the name Sudoku.
Rules and Terms
A Sudoku puzzle consists of 81 cells which are divided into nine rows, columns, and regions. The task now is to place the numbers from 1 to 9 in the empty cells so that in each column, row, and region 3 x 3. As a rule, each number appears only once in a 3 x 3 sub-grid. A Sudoku has at least 17 given numbers but there are usually 22 to 30.
A Sudoku is a puzzle-based game on logic but not math-based. It is possible to solve and make a Sudoku puzzle with few symbols or letters. An interesting little point is that there are 6,670,903,752,021,072,936,960 possible Sudoku puzzles. The players can play countless Sudoku puzzles per day and more new ones.
Sudoku Rue No. 1
Sudoku is played on a 9 x 9 square grid. Inside the rows and columns are 9 squares made up of 3 x 3 spaces. Each column, row, and square must be completed with the numbers 1 to 9. The numbers should not be repeated in a square, column, and row. It sounds complicated but it is fun.
Each Sudoku grid comes with spaces. The more spaces filled, the easier the game will be. The most difficult Sudoku puzzles have few spaces already filled.
Sudoku Rule No. 2
If there are all numbers except for 5 and 6 in the square. You can use the process of deductive and elimination reasoning to decide which numbers should be in each space. For example, if the top left square can have a number to complete the square. But based on the neighboring squares and rows, you cannot deduce which number to add in which space.
This means that you can ignore the top left square trying to fill the spaces in other areas of the grid.
Sudoku Rule No. 3
Sudoku is a game of reasoning and logic, so you don’t have to guess. If you don’t know which number to put in a certain space, then you can keep browsing the other areas of the grid until you find the right place for the right number. In Sudoku, you don’t have to force anything. The Sudoku rewards pattern recognition, perception, and patience, but not blind guesswork or blind luck.
Variants of Sudoku
Under the name Mini Sudoku, a 6 x 6 variant with 3 x 2 regions appears in the American newspaper USA Today. The goal of the game is the same as the standard Sudoku puzzle, but the puzzle only uses numbers from 1 to 6. A similar form named The Junior Sudoku has appeared in some newspapers like Daily Mail.
Alphabetical variations have appeared under the name of Wordoku. There is no functional difference in the puzzle unless the letters say something. Some variations such as in the TV Guide, include a word that is read along a main diagonal, column, row when resolved. Figure out the word ahead of time can be a solving aid. A Wordoku can contain other words in addition to the main word.
Roman Numbers Sudoku
Quadratum latinum is a variant of Sudoku with Roman numerals such as I, II, III, IV, …, IX. It is offered by Hebdomada aenigmatum, a monthly Latin puzzle and crossword magazine. Just like Wordoku, it has no functional difference compared to a normal Sudoku puzzle, but it does add visual difficulty by using Roman numerals.
Hyper Sudoku or Windoku uses the classic 9 x 9 and 3 x 3 grid and regions. It defines four additional 3 x 3 interior regions in which the numbers 1 through 9 must appear exactly once. It was invented by Peter Ritmeester and first published in the Dutch newspaper NRC Handelsblad in 2005 and in The International New York Times in 2007.
It was first called Hyper Sudoku in Will Shortz’s Favorite Sudoku Variations in 2006. It is also known as Windoku because the four inner regions of the grid are shaded. It looks like a window with glass bars.
Sudoku – A Number Place Game
A Sudoku is a fun number puzzle based on logic consisting of a 9 x 9 grid and small squares. The players can play it in the newspaper or other sources. There it comes with partially completed numbers in the sub-grid and the players have to place the numbers in the right place. To do so, players can use the deductive and elimination processes to place the right numbers in the grids.
With millions of possible number combinations and a wide range of levels of difficulty, it makes it a perfect logical-based puzzle game who wants to exercise their cognitive skills.