Logic Masters Deutschland e.V.

Chaos Construction: The grid has to be devided into nine regions of orthogonally connected cells. Each row, column and region has to contain the digits 1-9 once each.

Doubler: There are nine Doubler cells in the grid, exactly one in each row, column and region. The Doubler cells have to contain a complete set of the digits 1-9.
Additionally, each Doubler cell has to be in the same region as the cell RxCx with x being the digit in the Doubler cell.
The value of a Doubler cell is twice the digit in that cell.

Skyscraper: Each cell represents a skyscraper whose height is given by the value of the cell. A skyscraper blocks the view on all skyscrapers of the same or lower height standing behind it. Clues outside the grid give the number of skyscrapers seen from that direction in the corresponding row or column.

Have fun solving!

Sudoku on:
SudokuPad