**Brain Age **- a popular video game designed by Nintendo that features an electronic Sudoku game.

**Garns, Howard - **American who invented of the modern Sudoku puzzle. See also: Number Palace

**Hyper Sudoku** - a popular variation on standard Sudoku; The layout is just like standard Sudoku, but there are additional interior boxes sets in which the digits 1 through 9 must appear. Also known as NRC Sudoku, 4 Square Sudoku, and Windoku.

**Jigsaw Sudoku** - a variation on the standard Sudoku puzzle in which digits must be used once in each row and colum, but the 3x3 boxes are replaced with uniquely-shaped clusters of nine boxes (pentominos). Also known as nonomino Sudoku.

**Latin Square** - a table of numbers in which digits are used once in each row and column. It can be 3x3, 4x4, 5x5, 6x6, and so on. It's basically a completed Sudoku puzzle without the small 3x3 grid boxes. The Sudoku puzzle is based on Latin Square puzzles.

**Mini Sudoku** - a smaller version of Sudoku that is played on a 6x6 grid; This puzzle appears in *USA Today* newspapers. See also: Sub Doku

**Nikoli** - Japanese puzzle publisher who began printing Garns' Sudoku puzzles in 1986. Nikoli transformed Sudoku into a Japanese sensation in the late-80s. See also: Garns, Howard

**Nonomino Sudoku puzzle** - a variation on the standard Sudoku puzzle in which digits must be used once in each row and colum, but the 3x3 boxes are replaced with uniquely-shaped clusters of nine boxes (pentominos). Also known as Jigsaw Sudoku.

**Number Palace** - the name of the original Sudoku puzzle invented by Howard Garns in 1979

**Numeroliteral puzzle** - a Sudoku puzzles that uses combination of numbers and letters, these are usually done in 12x12 sudoku puzzles.

**Proper Sudoku puzzle** - a Sudoku puzzle that has a exactly one unique solution.

**Purely literal puzzle** - a Sudoku puzzle that has letters instead of numbers. (Also known as Alphabet Sudoku Puzzles)

**Satisfactory puzzle** - a Sudoku puzzle that does not require trial and error.

Suuji wa dokushin ni kagiru - an early name given to the sudoku puzzle; this translate to: "the numbers must be single"; The name was later shortened to Sudoku.

**Super Doku** - a Sudoku game with a grid that is larger than 9x9. Grids that are 12x12 are a common.

**Sub Doku** - a Sudoku game that has grids smaller than 9×9. The girds are commonly 4x4 or 6x6. These are sometimes called "Sudoku Puzzles for Kids" because they are easier to solve. See also: Mini Sudoku.

**Su Doku** - a commonly used variation of the spelling for Sudoku. It means "single number" in Japanese.

**Sudoku Cube** - a type of Rubik's cube; The cube must be twisted and turned so that the digits 1 through 9 nust appear on each of the cube's six sides.

**Triplet** - a set of 3 numbers in a row or column within the same block