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

- 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.

- 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.
- 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.

- 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.

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

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

- A dot between two cells indicates that the sum of the numbers in these cells is 10 or 11. If no dot between two cells the sum of the numbers in these cells must not be 10 or 11.

- A dot between two cells indicates that the sum of the numbers in these cells is 10 or 11. If no dot between two cells the sum of the numbers in these cells must not be 10 or 11.

- If absolute difference between two digits in neighbouring cells equals 1, then they are separated by a white dot. If the digit is a half of digit in the neighbouring cell, then they are separated by black dot. The dot between 1 and 2 can be either white or black.

- If absolute difference between two digits in neighbouring cells equals 1, then they are separated by a white dot. If the digit is a half of digit in the neighbouring cell, then they are separated by black dot. The dot between 1 and 2 can be either white or black.

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

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

- Identical digits do not touch each other diagonally.

- Identical digits do not touch each other diagonally.

- A number at the edge of the diagram indicates the difference between the highest and the lowest number in the first three cells in the corresponding row or column.

- A number at the edge of the diagram indicates the difference between the highest and the lowest number in the first three cells in the corresponding row or column.

- A number at the edge of the diagram indicates the difference between the first and the last number in the corresponding row or column.

- A number at the edge of the diagram indicates the difference between the first and the last number in the corresponding row or column.

- 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 at the edge of the diagram indicates the difference between the first and the last number in the corresponding row or column.

- Everywhere 2 odd and 2 even digits form a 2x2 checkerboard pattern, a Battenburg marking is given. A checkerboard pattern is a 2x2 area of cells where the top-left and bottom-right cells are of one type and the top-right and bottom-left cells are of another type. All possible dots are marked.

- Everywhere 2 odd and 2 even digits form a 2x2 checkerboard pattern, a Battenburg marking is given. A checkerboard pattern is a 2x2 area of cells where the top-left and bottom-right cells are of one type and the top-right and bottom-left cells are of another type. All possible dots are marked.

- 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.

- A dot between two cells indicates that the digits in the two cells form a double digit square number in the reading direction. there are no square numbers marked by a dot.

- A dot between two cells indicates that the digits in the two cells form a double digit square number in the reading direction. there are no square numbers marked by a dot.

- 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).

- 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.

- 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.

- 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.