Fill the grid with the digits 1 to 9. Each row, column and 3x3-box has exactly one of each digit. The four edges of the green square must contain the same set of digits (possibly in different orders). None edge of this square contains a repeated digit.
Fill the grid with the digits 1 to 9. The digits represent the height of the skyscraper in each cell. Each row, column and 3x3-box has exactly one of each digit. The clues along the edges tell you how many skyscrapers you can see from that vantage point. In the blue areas there must always be the same set of digits (possibly in different orders).
Fill in the grid so that every row, every column and 3x3 box contains the digits 1 through 9. Each diagonal has at most three different digits.
Fill in the grid so that every row, every column and the 3x3 boxes contain the digits 1 through 9. The sum of the digits within each sub-region is equal to the specified number. No digits can be repeated in any cage. All eight blue lines must use the same three digits. Each line must use three different digits.