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

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

- 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.
- 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.

- 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.

- If a shaded cell and a white cell are adjacent then the digit in the shaded cell is greater.

- If a shaded cell and a white cell are adjacent then the digit in the shaded cell is greater.

- 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.

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

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

- 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.

- 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.

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

- 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 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.

- 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.

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

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

- 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.

- Cells with shaded squares contain even digits. Cells with shaded circles contain odd digits.

- Cells with shaded squares contain even digits. Cells with shaded circles contain odd digits.

- 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 thermometer shapes are placed in the grid. Digits are strictly increasing from the round bulb of the thermometer to each flat end.

- Some thermometer shapes are placed in the grid. Digits are strictly increasing from the round bulb of the thermometer to each flat end.

- Some thermometer shapes are placed in the grid. Digits are strictly increasing from the round bulb of the thermometer to each flat end.