Tetromi-no!
(Published on 27. August 2026, 07:34 by EQD)
Normal Sudoku rules apply (place the digits 1-9 once each in every row, column, and 3x3 box).
German whisper: Adjacent digits on the green line must differ by at least 5.
Shaded parity cells: Shade the grid such that all even digits are shaded, and all odd digits are unshaded. Three shaded cells are given (in box 1).
Tetromi-no: A Tetromino is a group of 4 orthogonally connected cells that is entirely shaded or entirely unshaded. Shade the grid such that there are no Tetrominoes.
Solution code: Row 5, left to right
Comments
on 28. August 2026, 01:11 by Justalilguy
Enjoyed this one, thanks!
on 27. August 2026, 18:41 by EQD
This is my first puzzle submission, I accidentally set the difficulty based on an earlier version of this (that didn't have the three shaded cells at the start). Like Arheus noted, this is probably a medium difficulty puzzle.
Interestingly, the constraint is strong enough that there are only 2 possible ways to shade the grid even with NO grid furniture! I thought that was much less fun as it requires quite a bit of brute forcing to find them.
on 27. August 2026, 15:10 by Arheus
I didn't find it that difficult at all; the constraint was powerful enough to guide me through the entire puzzle. The solve flowed naturally and there was not one moment where I was stuck. A 3-3.5* for me. Great idea!
