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

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

- 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.

- 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.

- 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.

- If digit ‘n’ is placed in a cell with an arrow, digit ‘n+1’ must be placed in one of the cells pointed by the arrow.

- If digit ‘n’ is placed in a cell with an arrow, digit ‘n+1’ must be placed in one of the cells pointed by the arrow.

- The sum of the digits along the path of each arrow equals the digit in the circled cell. Digits may repeat within an arrow shape.

- The sum of the digits along the path of each arrow equals the digit in the circled cell. Digits may repeat within an arrow shape.

- 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.

- 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.

- 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.

- 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.

- 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.

- 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.

- 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.

- Cells with circles must contain digits 1-2-3, cells with squares must contain digits 4-5-6, blank cells must contains digits 7-8-9.

- Cells with circles must contain digits 1-2-3, cells with squares must contain digits 4-5-6, blank cells must contains digits 7-8-9.

- The number in a cell with an arrow indicates the distance to the cell with the number 9 in the direction the arrow points to.

- The number in a cell with an arrow indicates the distance to the cell with the number 9 in the direction the arrow points to.

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

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

- 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.

- Adjacent cells with digits summing to 5 are marked by V, while those summing to 10 are marked by X. Not 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. Not all possible V and X 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.