Su-duo-ku (aka Project "4D Sudoku") - Chapter II: String Sextet
(Published on 1. October 2026, 12:00 by Playmaker6174)
A follow-up puzzle of the previous Apollo & Artemis puzzle (that appeared just over a year ago), which focused around the double grids concept.
Chapter III is expected to come out soon.
Estimated difficulty is around lower side of 5/5 difficulty here, though some may find it easier than that.
Special thanks to Piatato for testing this one and the feedback!
Rules:
In this puzzle, two 9x9 Sudoku grids are given side by side and normal Sudoku rules apply to both grids.
1) Extra constraint for each grid:
+ Within each cage, digits don't repeat and they sum to the small number written in the top left corner of that cage. X is an unknown number that's required to be deduced.
+ Along each pink line, digits cannot repeat and they must form a set of consecutive digits which can be in any order.
Additionally, the sum of digits along each pink line cannot be bigger than 25.
+ Along each green line, two adjacent digits have the difference of at least 5.
+ Along each red line, two adjacent digits have the difference of at most 2.
+ Along each golden line, each set of three sequential cells must contain one digit from set {1,2,3}, one digit from set {4,5,6} and one digit from set {7,8,9}.
+ Box borders divide the blue line into smaller segments with the same sum of digits along each segment.
2) Interactions between both grids:
+ In this puzzle, a high digit is a digit that's at least 6 - i.e. a digit from the set {6,7,8,9}.
+ If a cell in the left grid contains a high digit then the cell in that exact same position in the right grid also has to contain a high digit, and vice versa.
+ Two particular cells marked by circles in both grids must contain the same digits.
(Note that other pairs of two cells in the exact same positions in both grids may or may not contain the same digits.)
Puzzle:
+ Penpa plus (recommended): Penpa link
+ Sudokupad: Both grids (Horizontal version) - Left grid only - Right grid only
Good luck and have fun solving!
Chapter III is expected to come out soon.
Estimated difficulty is around lower side of 5/5 difficulty here, though some may find it easier than that.
Special thanks to Piatato for testing this one and the feedback!
| Left grid |
|---|
| Right grid |
|---|
Rules:
In this puzzle, two 9x9 Sudoku grids are given side by side and normal Sudoku rules apply to both grids.
1) Extra constraint for each grid:
+ Within each cage, digits don't repeat and they sum to the small number written in the top left corner of that cage. X is an unknown number that's required to be deduced.
+ Along each pink line, digits cannot repeat and they must form a set of consecutive digits which can be in any order.
Additionally, the sum of digits along each pink line cannot be bigger than 25.
+ Along each green line, two adjacent digits have the difference of at least 5.
+ Along each red line, two adjacent digits have the difference of at most 2.
+ Along each golden line, each set of three sequential cells must contain one digit from set {1,2,3}, one digit from set {4,5,6} and one digit from set {7,8,9}.
+ Box borders divide the blue line into smaller segments with the same sum of digits along each segment.
2) Interactions between both grids:
+ In this puzzle, a high digit is a digit that's at least 6 - i.e. a digit from the set {6,7,8,9}.
+ If a cell in the left grid contains a high digit then the cell in that exact same position in the right grid also has to contain a high digit, and vice versa.
+ Two particular cells marked by circles in both grids must contain the same digits.
(Note that other pairs of two cells in the exact same positions in both grids may or may not contain the same digits.)
Puzzle:
+ Penpa plus (recommended): Penpa link
+ Sudokupad: Both grids (Horizontal version) - Left grid only - Right grid only
Good luck and have fun solving!
Solution code: Enter column 8 in the left grid first, then column 8 in the right grid. Both columns are entered from top to bottom.
Last changed on -
Solved by Piatato, killer_rectangle, han233ing, Mr_tn
Comments
on 1. October 2026, 14:24 by Piatato
Great interactions, thanks!
