Logic Masters Deutschland e.V.

This puzzle was set to be a part of a gift pack for a very special birthday, NEWS! Thank you for all you do for our little puzzling community, I am so glad I was able give something back to you!

Thanks to everyone involved in the pack for helping make it happen!

P.S. Yes, the East West is backwards, it spells NEWS this way!

Rules:

• Quad Doppelgänger Sudoku:
  • Fill each cell of the four 4x4 grids such that every row, column and 2x2 box contains a 0 and three different digits from 1-4.
  • Within a 4x4, no two rows, no two columns, and no two boxes may be missing the same digit.
  • For each 0, the digits missing in its row, column, and box must be three different digits.
  • Fill each cell between 4x4s with the digit missing from the corresponding row or column.
  • Fill each cell in the central 2x2 with the digit missing from the corresponding box.
  • Orthogonally adjacent grids share the same missing digits from either rows or columns (e.g. NW and NE grids have the same digits missing from rows).
  • All grids share the same missing digits from boxes.

• Digits along an arrow sum to the digit in the arrow's bulb. Cells without digits do not affect the clue.