The Terms and Jargon of Sudoku

Sudoku is a math logic puzzle game. This popular game was invented in 1979 by an America named Howard Garns. It became popular in Japan in 1986 when the game was first published in that country by Nikoli Co. Ltd.. It came back to the United States by 2005 and has since spread in popularity around the world.

As with any game, Sudoku has its own terms and jargon. Sudoku has some appearance to a crossword puzzle. Both are printed on a square grid. A typical Sudoku grid has nine rows and nine columns. These are divided into nine equal boxes. The shape of the whole grid appears like that of a tic tac toe game. Within each box are nine cells. There are 81 total square cells within the whole grid. To avoid confusion the boxes and cells are not called squares. The nine equal boxes are also referred to as blocks.

Within the grid, three vertically stacked boxes are called a stack. There are three stacks in a typical Sudoku grid. There are also three bands within the grid because three horizontally connected blocks are called a band. The term chute is used to describe a band or stack. Therefore, a Sudoku grid has three bands, three stacks, and three chutes.

If this hasn't confused you enough, there are also sub-areas called regions. Regions are any equal-sized partitioned shapes that relate to other equal-sized partitioned shapes within the grid. There are variants to the traditional shaped regions. Regions can be equal-sized but not equal shaped. These are generally used in advanced Sudoku puzzles.

The rows, columns, and regions within a Sudoku grid are collectively referred to as units or scopes. The grid itself, therefore, has 27 units or scopes. Usually a composite row times column designation is used to denote the size of the puzzle. A 9x9 size is typical of a Sudoku puzzle.

The term puzzle is used to describe a partially completed grid. Clues (also sometimes called givens) are the initially given numbers within the grid. A Sudoku puzzle that has a single, unique solution is called a proper puzzle. In a proper puzzle each digit between 1 and 9 appears only once within each row and column and box.

As stated before, there are variants within a Sudoku puzzle format. The 9 x 9 grid format can also be a 6 x 6 grid format. This would allow for 3 x 2 rectangular regions within the Sudoku puzzle. In addition to variants by size, there can also be constraint and clue variants.