Normal Sudoku rules apply.
Full Rank Arrows: There are twenty marked diagonals in the grid with seven or more digits. A value in an external cell represents the rank of the number formed by reading the first seven digits along that diagonal from that direction, where (1) is the lowest such diagonal and (20) is the highest.
Colored Arrows: The main diagonals of the puzzle have additional restrictions.
Parity: Create a valid nine cell parity line along the main diagonal indicated by the red arrows. Adjacent digits along the diagonal must not be both odd or both even.
Modular: Create a valid nine cell modular line along the main diagonal indicated by the blue arrows. Every set of three adjacent digits must have different remainders when divided by 3. (147, 258, 369)
Dutch Whisper: Adjacent digits along an orange line must differ by 4 or more.
Quadruples: Digits in large white circles must appear in one of the four surrounding cells.
Solution code: Row 9
on 1. January 2026, 23:02 by FireTruckFuel
Changed solution code to row 9.
on 17. December 2025, 13:14 by marajade
Thought I'd take a crack at your 3* puzzles after chickening out of them when I was going through your back catalog the other day. This was such an interesting puzzle to solve! The way the quadruple & rank constraints interacted was very fun to untangle.
on 25. November 2025, 14:45 by QuiltyAsCharged
Very nice puzzle with a unique take on full rank
on 26. October 2025, 10:43 by kroutu
Are you sure about the solution code ?
ok never mind, I realized my mistake (for others who would do the same : 2x 7 digits only)