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

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

- 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.
- 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.

- 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.

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

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

- 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.

- Each number outside the grid is the sum of the first X numbers placed in the corresponding direction, where X is equal to the first number placed in that direction.
- There are some dots between cells. The numbers on each side of a dot must always be consecutive. Not all possible dots are marked.

- Each number outside the grid is the sum of the first X numbers placed in the corresponding direction, where X is equal to the first number placed in that direction.
- There are some dots between cells. The numbers on each side of a dot must always be consecutive. Not all possible dots are marked.

- Each number outside the grid is the sum of the first X numbers placed in the corresponding direction, where X is equal to the first number placed in that direction.

- 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.

- There are some dots between cells. The numbers on each side of a dot must always be consecutive. All possible dots are marked.

- There are some dots between cells. The numbers on each side of a dot must always be consecutive. All possible dots are marked.

- The number in a cell with an arrow must not be repeated in a cell the arrow points to.

- The number in a cell with an arrow must not be repeated in a cell the arrow points to.

- There are some dots between cells. The numbers on each side of a dot must always be consecutive. All possible dots are marked.

- 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.

- A number between two cells indicates the difference of the numbers in these cells. A number between four cells indicates the difference between two diagonally adjacent cells, either top left + right bottom (\) or top right + bottom left (/). If one of the characters < or > is specified the apex of the angle points to the smaller of these numbers.

- A number between two cells indicates the difference of the numbers in these cells. A number between four cells indicates the difference between two diagonally adjacent cells, either top left + right bottom (\) or top right + bottom left (/). If one of the characters < or > is specified the apex of the angle points to the smaller of these numbers.

- There are some dots between cells. The numbers on each side of a dot must always be consecutive. Not all possible dots are marked.
- 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.

- The four corner boxes contain the same digit in symmetric positions about the centre.

- The four corner boxes contain the same digit in symmetric positions about the centre.

- 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.

- Numbers in the red circle are not allowed appears in four squares which is nearby the intersection of row and column red circles.

- Numbers in the red circle are not allowed appears in four squares which is nearby the intersection of row and column red circles.

- Digits have to be place in accordance with the “greater than” signs.

- Digits have to be place in accordance with the “greater than” signs.