Logic Masters Deutschland e.V.

I have a love-hate relationship with Yin-Yang puzzles. Yin-Yang is a Taoist emblem "representing the balance, interdependence, and transformation of opposing yet complementary forces in the universe."

So here's a tough one to brighten ... or possibly darken ... your day. Maybe it will encourage you to put in some extra time at work, or take a well-deserved break. Looking forward to the upcoming winter, or already missing summer? Eat a hot, spicy, filling meal, or munch on a few celery sticks. You can solve the puzzle at noon, or midnight. Or anytime in between.

The Rules:
• Normal Sudoku Rules Apply.
• Cells separated by a white dot must contain consecutive digits, digits in cells separated by a black dot must be in a 2:1 ratio. ALL POSSIBLE DOTS ARE GIVEN.
• Shade some cells such that all shaded cells are orthogonally connected, all unshaded cells are orthogonally connected, and no 2x2 cluster of cells is entirely shaded or unshaded (Yin Yang rules).
• All orthogonally adjacent cells that separate shaded and unshaded regions must contain digits that differ by at least 3.
• Heavy black lines denote separation between shaded and unshaded regions.
• Digits in cells separated by an X must sum to 10. For each X, BOTH cells are either in the shaded or unshaded region. Not all X's are shown.



Solve Online here (right-click and open in new tab):
Darkness and Light (Yin-Yang) (Sudokupad)

The Sudoku/Kropki is medium difficulty - 3 star maybe. The Yin Yang pattern is a bit more difficult. Even if you solve the Sudoku, the solution code forces you to finish the shading!

Leave a comment and let me know how you like it!

Puzzle by David Workman (aka "HalfBakedLunatic")


To clarify the solution code, the cells in Box 5 are numbered 1 (upper left) to 9 (lower right). Give the cell numbers, in order, of the five cells in the same group.