Logic Masters Deutschland e.V.

Psycho Look-and-Say Killers are one of my favorite indexing constraints. They index digits across the grid in a unique way. I set this puzzle for a recent Speed Setting Competition and came away with first place, to my great surprise. I hope you enjoy it!

There is also an introductory puzzle available for an easier introduction to the constraint: Intro to Psycho Look-and-Say Killers

Rules:

• Normal Sudoku rules apply, along with Arrow and Psycho Look-and-Say Killers.
• Sudoku: Place the digits 1-9 once each in every row, column, and 3x3 box.
• Psycho Look-and-Say Killers: Digits in pink cages may not repeat. Each digit in a cage indexes a cell in the grid. The cell is located in the *box* with the digit's number, in the *same position* within the box as the cell containing the digit. A digit may index its own cell. The cage clue should be read as a look-and-say clue that counts the number of times a digit appears in all the indexed cells.
• For example, if the clue was 28, then there would be exactly two 8's in the cells indexed by the digits in the cage.
• Arrow: Digits on an arrow line sum to the digit in the connected circle.

Streamers have permission to use this puzzle.

Play in SudokuPad

Example:

• In the example image, there must be two 8’s in the cells indexed by the 28 cage in box 2.
• The digit 1 in that cage indexes to *box* 1, and then to the cell in the *same position* in that box as the digit 1 in its box (the top-middle cell).
• The digit 3 in that cage indexes to *box* 3, and then to the cell in the *same position* in that box as the digit 3 in its box (the middle-middle cell).
• Since there must be two 8’s in the indexed cells, both indexed cells must contain an 8.