Logic Masters Deutschland e.V.

Changelings have invaded Sudokuville and are causing mayhem and confusion! Is anyone who they say they are? Killers and witnesses look alike, people are missing, other people look exactly like their neighbors, and nobody seems to know anything for sure!

• Normal sudoku rules apply: Place the digits 1-9 once each in every row, column, and 3x3 box.
• Changelings: Identify 9 Changelings in the grid such that there is one Changeling in every row, column, and box. Each Changeling must contain a different digit. The value of a Changeling is equal to the digit in one of the (up to 4) cells orthogonally adjacent to it, regardless of its own digit. Which orthogonally adjacent cell the Changeling imitates must be determined. Any cell that is not a Changeling retains its digit as its value.
• Ambiguous clues: A number outside the grid is either a valid Up to N clue or a valid Look and Say clue, but never both. A cage is either a valid Killer cage, or a valid Look and Say cage, but never both.
• Up to N: An Up to N clue outside Row N or Column N indicates the sum of all values up to a cell that contains the value N. That cell itself is not included in the sum. If the value N appears twice in the row/column, an Up to N sum may stop at either instance of the value N. If the value N does not appear in the row/column, an Up to N sum would give the sum of the entire row/column.
• Killer: Values in a Killer cage sum to the number in the top left corner. Digits may not repeat in a cage, but values may.
• Look and Say: A Look and Say clue reading XY (either outside of the grid or within a cage) indicates that the value Y appears X times in the clued row/column/cage.

Solve in SudokuPad