European Union
(Published on 14. February 2025, 10:34 by koarla)
Rules
Normal Sudoku rules: Place the digits 1 to 9 exactly once in each row, column and box.
United in Diversity: Every 2×2 square of cells (yes, they overlap) must contain one low digit (123), one middle digit (456) and one high digit (789).
Good neighbours: Cells separated by a star contain adjacent digits.
Odd / even: Cells marked with a grey circle contain odd digits. Cells marked with a grey square contain even digits.
Play hard version on SudokuPad (without odd / even constraint)
Solution code: Column 5 from top to bottom
Comments
on 16. February 2025, 09:27 by PuzzlePatzer
I love a colouring puzzle :) and this one is a great one. thanks for sharing!
on 14. February 2025, 16:47 by gfoot
Nice approachable global entropy puzzle! (I did the hard version, it was still very approachable.)
on 14. February 2025, 14:39 by Bankey
Good entropic fun. Difficulty (hard version) is max 3*. Thanks for sharing, @ koarla :).
on 14. February 2025, 13:50 by Lorena
This reminded me of the joy and pride in my grandfather’s face the day our country was accepted into the EU. This was decades ago and I was very small but it’s a day I will never forget. Thank you for the lovely puzzle.
on 14. February 2025, 12:55 by ghaia
really nice puzzle! my first time dabbling in any entropy at all, did the normal version, at most a 2 star difficulty rating from me. Very fun though!
on 14. February 2025, 12:01 by damo_89
Agree, the harder version is still pretty approachable if you are familiar with 2x2 global entropy, and cute colouring to resolve the last triples.
on 14. February 2025, 11:15 by Mad-Tyas
Nice puzzle! I think the difficulty (of the hard version) is at most 2/5.
