Logic Masters Deutschland e.V.

I recently came up with the idea of the shadow grid and shadow clues while watching Stranger Things. I hope you like it!

Rules:

• Normal sudoku rules apply.
• Each cell N in the solved grid has a corresponding shadow cell whose value is 10-N. The grid contains normal clues related to normal cells, and shadow clues related to shadow cells. The solver must determine which clues are shadow clues. There are exactly 3 shadow clues in the grid.
• Digits within a cage must add up to the total in the corner. Digits cannot repeat within a cage.

Note: I included a graphical explanation of the shadow cells in this puzzle's sequel.

Play online on SudokuPad