Borrower
(Published on 27. March 2026, 13:00 by SennyK)
Today I am happy to share an easy puzzle with Copycat constraint which I believe was invented by Scojo and first used in the Copycat Copycat puzzle :-)
I hope you will enjoy and I would be really grateful for all the comments and ratings.
Normal 6x6 sudoku rules apply.
Copycat Cells: There are exactly 6 Copycat Cells in the grid, one in each row, column, and 2x3 box. The value of a Copycat Cell is the digit in the cell rotationally opposite itself in the grid (180° rotation about the center of the grid). For example, if r2c3 is a Copycat Cell containing the digit 3, and r5c4 contains the digit 4, the value of r2c3 is the digit in r5c4, which is 4.
Digit in a Copycat Cell is its row number.
X: Values in cells joined by an X sum to 10. Not all Xs are necessarily given.
If you liked this puzzle, I recommend trying out my other puzzles: The Erica Series:★☆☆☆☆: 1, 2, 4, 5, 6, 12, 15, 17, 23, 26, 27, 31, 32, 46, 47
★★☆☆☆: 3, 7, 8, 10, 11, 13, 14, 16, 18, 20, 24, 25, 29, 30, 34, 35, 38, 40, 42, 45
★★★☆☆: 9, 19, 21, 22, 28, 33, 37, 38, 41, 44, 45
★★★★☆: 36, 39, 43 German Sum Series:
★★☆☆☆: German Sum Introduction
Shading/Ying-Yang:
★★☆☆☆: Pretty Odd Shaded Area
★★★☆☆: (+5)-Yang, Negative 8 YY
★★★★☆: Aim High! (YY)
★★★★★: Why-Why? Modifiers:
★★★☆☆: Modified Flat Mates, Neighbourhood Watch Fog of War:
★☆☆☆☆: Erica 12, Erica 17
★★☆☆☆: It's What You Do in the Dark That Puts You in the Light, Find It All, What the Fog?, Erica 20, Erica 29
★★★☆☆: Broken Flashlight in the Dark Pencil Puzzle/Sudoku Hybrid:
★★☆☆☆: Masyu (Short) Sudoku, Heyawake Sudoku (Given Regions)
★★★☆☆: Tetromino Sudoku
★★★★★: Heyawake Sudoku
Pairometers:
★★☆☆☆: Pairometers (6x6 Pack 1), Pairometers
★★★☆☆: Pairometers (6x6 Pack 2), Pairometers (6x6 Pack 3) Various Puzzles:
★☆☆☆☆: Blown Fuses in Electrical Installation, Let Me Introduce Myself, French Wrench, GAS Regional Constraints, Quadsumes, Snack Latin Arrows, Sarah
★★☆☆☆: Symmetrical Fan, Night Club, Important Hour on the Clock, What Was the Sum Again?, Disgroup Joints, 10-Arrows, Antiking Dutch Skyscrapers, (Not so) Little Killers, Indexing Sword, Larna's HoneyMoon
★★★☆☆: Cops & Robbers, Positive Symmetry, Doppelgänger Killer 1-25, Region Whisper Line, Christmas Chaos
★★★★☆: Liars. Liars Everywhere., Sandwiched XV Squishmates, Fireworks 2025, (Yin)German Pairrows, Little Galaxy, 2x Solution
★★★★★: Any NEWS?, Potentially Pointer, Possibly Parity Party
Solution code: Sixth (6th) row of the grid from left to right.
Comments
on 30. March 2026, 20:07 by Killer Joe
For some reason my brain skipped the rule in red. Of course I read the rules again and started to understand the negative constraint doing a lot of work in this puzzle. Nicely done.
on 27. March 2026, 19:54 by abadx
The copycat constraint is very restrained as it fixes the value of the copycat cell, so once all rules are understood and internalized, solve is quite easy. I would rate it 2* just because the constraint is a bit "naughty".
on 27. March 2026, 19:22 by SennyK
Link Updated
on 27. March 2026, 19:21 by faltenin
Same as a previous commenter, I was stuck until I read the rules again !
on 27. March 2026, 18:15 by Plok
Thank you for the nice puzzle.
Just a small remark on the rules. in the this puzzle you use XV variant or XV pair variant. X-sums (which you mention) is the variant where clues outside the grid give the sum of the first X digits in a row or column.
SK: Thank you! Puzzle was initially created for Sudoku Adventure series where Xs are called X-Sums. I will amend it, thanks!
on 27. March 2026, 15:33 by sujoyku
I had the same experience as TrivialHomology. Fun Snack once you follow the full ruleset. Thank you, SennyK!
on 27. March 2026, 14:47 by Ginge
Delightful little puzzle
on 27. March 2026, 14:39 by TrivialHomology
I spent a few minutes wondering how this could possibly be 1* difficulty. Then I read the rules again and found out that a digit in a Copycat Cell is its row number :)
Fun puzzle!
on 27. March 2026, 14:24 by Calvinball
Really enjoyed this, a great introduction to Copycat!
on 27. March 2026, 13:53 by Ginge
Delightful little puzzle
