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.
- 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.

- 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.

- Numbers with arrows indicate sum of the numbers in each direction.

- Numbers with arrows indicate sum of the numbers in each direction.

- 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 same numbers are not chess-knight move connected.

- The same numbers are not chess-knight move connected.

- 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.

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

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

- The same numbers are not chess-knight move connected.

- The same numbers are not chess-knight move connected.

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

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

- 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.

- 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.

- Numbers with arrows indicate sum of the numbers in each direction.

- Numbers with arrows indicate sum of the numbers in each direction.

- 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.

- Adjacent cells with digits summing to 5 are marked by V, while those summing to 10 are marked by X. All possible V and X are marked.

- Adjacent cells with digits summing to 5 are marked by V, while those summing to 10 are marked by X. All possible V and X are marked.

- Digits do not repeat along the marked diagonals.

- Digits do not repeat along the marked diagonals.

- Some intersections of the grid lines are marked by a number and an operator (+, -, x, /) in a circle. The number is the result of the operation, applied to both pairs of diagonally opposite cells. An E in the circle indicates that all four adjacent digits are even, while an O indicates that all four adjacent digits are odd.

- Some intersections of the grid lines are marked by a number and an operator (+, -, x, /) in a circle. The number is the result of the operation, applied to both pairs of diagonally opposite cells. An E in the circle indicates that all four adjacent digits are even, while an O indicates that all four adjacent digits are odd.

- Consider each number to be the height of a building. The numbers outside the grid indicate how many buildings can be seen when looking in that direction (taller buildings conceal smaller buildings behind them).

- Consider each number to be the height of a building. The numbers outside the grid indicate how many buildings can be seen when looking in that direction (taller buildings conceal smaller buildings behind them).

- 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.

- The arrows outside the grid indicate that the nearest three digits in the corresponding direction are in ascending or descending order (the highest number is always in the direction of the arrow). All possible arrows are given, so if there is no arrow, the first three digits do not form an increasing sequence in either direction.

- The arrows outside the grid indicate that the nearest three digits in the corresponding direction are in ascending or descending order (the highest number is always in the direction of the arrow). All possible arrows are given, so if there is no arrow, the first three digits do not form an increasing sequence in either direction.