Today Sudoku contains very many types of variant Sudoku, more types of Sudoku puzzles are still under continuous development, please continue to pay attention to Sudoku today.

- Place a digit from 1 to 9 into each of the empty squares so that each digit appears exactly once in each of the rows, columns and the nine outlined 3x3 regions.
- Digits do not repeat along the marked diagonals.

- Place a digit from 1 to 9 into each of the empty squares so that each digit appears exactly once in each of the rows, columns and the nine outlined 3x3 regions.
- Digits do not repeat along the marked diagonals.

- Place a digit from 1 to 9 into each of the empty squares so that each digit appears exactly once in each of the rows, columns and the nine outlined 3x3 regions.
- Grey cells in the grid represent many cloned areas. Digits in these areas on corresponding positions must be identical. Cloned areas are only moved, without rotation or reflection.

- Grey cells in the grid represent many cloned areas. Digits in these areas on corresponding positions must be identical. Cloned areas are only moved, without rotation or reflection.

- Digits along each marked line are either all odd or all even.

- Digits along each marked line are either all odd or all even.

- Arrows and numbers outside gridding means how many different numbers in corresponding direction grid.

- Arrows and numbers outside gridding means how many different numbers in corresponding direction grid.

- A cross between two cells indicates that the product of the numbers in these cells is less than 10. A plus between two cells indicates that the sum of the numbers in these cells is less than 10. If the sum and product are less than 10, then there is a cross between these cells. If there is no sign between two cells, then both sum and product are at least 10.

- A cross between two cells indicates that the product of the numbers in these cells is less than 10. A plus between two cells indicates that the sum of the numbers in these cells is less than 10. If the sum and product are less than 10, then there is a cross between these cells. If there is no sign between two cells, then both sum and product are at least 10.

- Digits do not repeat along the marked diagonals.

- Digits do not repeat along the marked diagonals.

- An arrow in a cell indicates that the number in this cell is repeated at least once in the direction the arrow points to.

- An arrow in a cell indicates that the number in this cell is repeated at least once in the direction the arrow points to.

- The digits in two orthogonally adjacent cells cannot have a sum of either 5 or 10.

- The digits in two orthogonally adjacent cells cannot have a sum of either 5 or 10.

- Digits in adjacent cells cannot be consecutive.

- Digits in adjacent cells cannot be consecutive.

- Digits along each marked line are either all odd or all even.

- Digits along each marked line are either all odd or all even.

- Apply Classic Sudoku rules. Within each coloured region each digit must appear exactly once.

- Apply Classic Sudoku rules. Within each coloured region each digit must appear exactly once.

- Each number at the intersection of four cells is the sum of digits in those four cells.

- Each number at the intersection of four cells is the sum of digits in those four cells.

- Each of the four shaded 3x3 boxes contains each digit from 1 to 9.

- Each of the four shaded 3x3 boxes contains each digit from 1 to 9.

- Digits outside the grid indicate the sum of the first 3 digits in the corresponding direction.

- Digits outside the grid indicate the sum of the first 3 digits in the corresponding direction.

- A number in a squared cell indicates how many different numbers the four diagonally adjacent cells contain. A number in a circled cell indicates how many different numbers the eight orthogonally and diagonally adjacent cells contain.

- A number in a squared cell indicates how many different numbers the four diagonally adjacent cells contain. A number in a circled cell indicates how many different numbers the eight orthogonally and diagonally adjacent cells contain.

- The diagram is a toroid; some of the 3×3 regions don't end at the right (lower) edge of the diagram but continue at the left (upper) edge of the diagram.

- The diagram is a toroid; some of the 3×3 regions don't end at the right (lower) edge of the diagram but continue at the left (upper) edge of the diagram.

- The connected shaded cells contain each digit from 1 to 9.

- The connected shaded cells contain each digit from 1 to 9.

- An arrow in a cell indicates that the number in this cell is repeated at least once in the direction the arrow points to.

- Digits do not repeat along the marked diagonals.

- Digits do not repeat along the marked diagonals.

- A dot between two cells indicates that the result of at least one of the basic operations (addition, subtraction, multiplication, division) of the numbers in these two cells is 8. Is the dot missing, no one of the basic operations results in an 8.

- A dot between two cells indicates that the result of at least one of the basic operations (addition, subtraction, multiplication, division) of the numbers in these two cells is 8. Is the dot missing, no one of the basic operations results in an 8.