Common Sudoku Variants
Puzzle shown: Classic Sudoku by Cracking the Cryptic
There are 9 rows, 9 columns, and 9 regions. Each square must be filled with a number from to , and numbers may not repeat in the same row/column/region.
In almost every sudoku puzzle, these rules will apply.
Puzzle shown: Killer Sudoku by Serkan Yürekli
Orthogonally connected cages are drawn. No numbers in the same cage may repeat, and if a sum is indicated in the cage, the numbers in the cage add up to said sum.
Numbers must be strictly increasing from the bulb of the thermometer to the end.
Numbers on the arrow must add to the number in the circle. Numbers may repeat if permitted by other Sudoku rules.
Renban lines must contain consecutive digits in any order.
Two directly connected digits on a German whisper must differ by 5 or more.
Two digits separated by an X must sum to 10. Two digits separated by a V must sum to 5. (These digits are orthogonally adjacent.)
If two orthogonal digits are separated by a white dot, they must be consecutive. If two orthogonal digits are separated by a black dot, one must be double the other.
The digits on the diagonal indicated by a Little Killer must add to the sum indicated by the Little Killer. Digits on the diagonal may repeat.
The first X digits in a row or column in the direction of an X-Sum, where X is the first digit seen in that row or column, must add to the indicated sum.
Gray circles must contain odd digits, and gray squares must contain even digits.
Digits on a between line must lie between the digits on the endpoints. Digits may repeat on the line.
A square must contain a digit different from every other square a knight’s move away (2 over and 1 across).
A square must contain a digit different from every other square a king’s move away (sharing a vertex).