# Sudoku Variants

There are numerous ways to vary the basic Sudoku format. Yet, only a few variations have developed a loyal group of supporters. Most variations are regarded as a curiosity.

## Variant Types

There are many ways to vary a Sudoku. Here are only a few examples:

To complicate things, a puzzle maker can combine several of these alterations.

## Popular Variants

These often appear in newspapers or feature in dedicated puzzle books.

Killer | Sum-Sudoku | Samunamupure
Given numbers are replaced by cages labeled with the sum of the digits inside the cage. This is by far the most popular Sudoku variation.
Jigsaw | Nonomino | Squiggly | Irregular Sudoku
3x3 boxes are replaced by regions with an irregular shape.
Sudoku-X
The 2 diagonals also require digits 1 through 9.
Windoku | Hypersudoku | NRC-Sudoku
There are 4 additional 3x3 boxes in the grid which must also contain digits 1 through 9.
Samurai | Gattai-5
A puzzle with 5 partially overlapping Sudoku grids.

## Common Variants

There appear occasionally in newspapers, but have dedicated websites and appear on a regular basis in Sudoku variant books.

Clueless
A puzzle with 9 Sudoku grids where the center nonets form a 10th Sudoku grid.
Flower Sudoku
A puzzle where 4 Sudoku grids each overlap 6 boxes of a central Sudoku grid.
Hanidoku
A puzzle with hexagonal cells that must contain a consecutive series of digits.
Greater Than
A puzzle where the given digits are replaced by greater-than signs.
Consecutive Puzzle
A puzzle where any 2 adjacent cells containing consecutive digits are marked on the border between the cells.
Non-Consecutive
A puzzle where 2 adjacent cells cannot contain consecutive digits.

## Other Variants

These variants are less common.

Sudoku3D
A 3D implementation of a classic sudoku. Sudoku3D is a single puzzle on a surface of 4x4x4 cube.
Center Dot
An ordinary Sudoku with an extra constraint involving the center square of each box.
Asterisk
An ordinary Sudoku with an extra constraint which looks like an asterisk.
Sukaku
An ordinary Sudoku, except that the starting position contains pencilmarks instead of givens.
Sumo | Gattai-13
A puzzle with 13 partially overlapping Sudoku grids.
Shaolin | Gattai-25
A puzzle with 25 partially overlapping Sudoku grids.
Kansuko
A 3x9 grid with a sum column as an additional constraint.