Sudoku (also known as "Number Place") is a placement puzzle. The puzzle is most frequently a
In some sudokus main diagonals also contain the digits 1 through 9. This variant is called Sudoku X ("Diagonal Sudoku" or "Kokonotsu"). Use the check box Diagonals for such sudokus.
Argyle Sudoku contains additional diagonals; every marked diagonal line contains each digit not more than once. The argyle pattern is derived from the tartan of Clan Campbell, in eastern Scotland.
Also the puzzle may contain the regions of random (irregular) shape; this variant is called Jigsaw Sudoku ("Geometry Sudoku", "Geometry Number Place", "Irregular Sudoku", "Kikagaku Nanpure"):
Godoku (also known as "Wordoku") is similar to sudoku, but uses letters instead of numbers. Once the grid is complete, the hidden word may be revealed.
In Asterisk Sudoku there is an additional area, shown on the grid by shading nine specially selected cells. Those nine cells must also contain 1 to 9.
Girandola is an ordinary sudoku with one extra group of cells. This group must also contain digits 1 through 9. (Girandola is a kind of revolving firework.)
Center Dot is a variant of sudoku, where central cells of each region form an extra region. This region must contain digits 1 through 9.
Sudoku may contain additional four regions
Sudoku-DG (also known as "Offset Sudoku") contains 9 disjoint groups in the puzzle, one for each relative box position. Each group has a distinct color. The group of 9 cells with the same color must also contain digits 1 through 9.
In Anti-Knight Sudoku all cells at a chess knight move (at a distance of 2 by 1) must hold different numbers.
In Anti-King Sudoku ("Touchless Sudoku") equal digits can be neither orthogonally nor diagonally adjacent.
In Anti Diagonal Sudoku each diagonal has at most three different digits.
In Killer Sudoku, sub-regions have specified sums, and no number can be repeated within a region. This variant also called "Sums Sudoku", "Sums Number Place", "Samunamupure", "Kikagaku Nampure".
Greater Than Sudoku is the variation of the original sudoku. In addition, greater than or less than signs (">" or "<") in the walls indicate that one cell's number is greater than or less than an adjacent cell's number. Also called "Compdoku".
Even-Odd Sudoku: fill in the grid so that every row, every column, and every
Sometimes not all even or odd digits are marked in the task. Use the check box Not all gray cells are marked for such sudokus.
In Consecutive Sudoku ("1-away Disallowed Number Place"), all the places where orthogonally adjacent cells are consecutive numbers have been specially marked.
In Non-Consecutive Sudoku no two adjacent cells have consecutive values. For example, if a cell contains 3, then any neighbouring square cannot contain either 2 or 4.
Kropki Sudoku (from Polish, literally "dots"; also known as "Dots Sudoku") is the variation of the original sudoku. If absolute difference between two digits in neighboring cells equals 1, then they are separated by a white dot. If the digit is a half of digit in the neighboring cell, then they are separated by black dot. The dot between 1 and 2 can be either white or black.
Sukaku ("Suuji Kakure"; also known as "Pencilmark Sudoku") has 81 groups of digits in a
Chain Sudoku (also known as "Strimko") consists of a group of circles arranged in a square grid and containing given clues in various places. The object is to fill all empty circles so that the digits appear exactly once in each row, column and chain.
The program can solve and create puzzles from
Frame Sudoku (also known as "Outside Sum Sudoku") consists of an empty grid. Numbers in the outside frame equal the sum of the first three numbers in the corresponding row or column in the given direction.
Skyscraper Sudoku contains clues around the edge. The task is to place digits in the grid. Each digit represents the height of the skyscraper in each cell. The numbers outside the grid represent the number of skyscrapers seen from the corresponding direction.
Tripod Sudoku is a variation of sudoku, where the borders of regions are not defined. The goal is to fill the grid with digits and divide the grid into regions. Each digit appears exactly once in every row, column and region. All points where three lines meet are given. There are no points where four lines meet.
The program can solve and create puzzles from
Sudoku Mine combines Sudoku puzzle with Minesweeper game. The goal is to place three mines in every row, column and region. The digits in the grid represent the number of mines in the neighbouring cells.
Sujiken (from Japanese "sujikai", literally "diagonal") is a variation of Sudoku, invented by George Heineman (USA). The puzzle consists of a triangular grid of cells containing digits from 1 to 9. The objective is to fill a grid with digits so that each cell contains a digit and no digit is repeated in any column, row and diagonal in any direction. Also, no digit occurs twice in any of the three larger
The formats of sudoku files: