Logic Masters Deutschland e.V.

Kneel Diamond

(Published on 14. August 2026, 16:43 by JamesCullum)

♦ ♦ ♦ ♦ ♦
KNEEL DIAMOND
A sudoku spectacular in four mathematically questionable acts
by James Cullum
♫ Please kneel responsibly. ♫
▶ PLAY KNEEL DIAMOND IN SUDOKUPAD
♫ Tonight's Set List ♫
Four rules. No encore required.
1. Sudoku — The Classic Opener
Place the digits 1–9 in every row, column, and 3×3 box without repetition.
2. Ratio Arrows — Double Diamond
Each circled bulb contains a normal Sudoku digit d.

Its effective VALUE is the sum of the digits on its arrow shaft.

That VALUE is either
d ÷ 2    or    2d
Apparently the circles couldn't decide whether they wanted half the attention or twice as much.
3. Value Sandwiches — You Don't Bring Me Flowers, You Bring Me Bread
Digits 1 and 9 are the bread and are excluded from the sum.

Every cell strictly between them contributes its VALUE:
Ordinary cells use their digit.
Ratio-circle cells use their effective arrow value.
Finally, a sandwich where counting the filling is considerably harder than eating it.
4. Region Sum Lines — Same Song, Different Box
Box borders split each line into segments.

Every segment on the same line has the same DIGIT sum.
Different segment. Same total. The band has been rehearsing.
♦ GOOD LUCK, SOLVER ♦
May your arrows have VALUE,
your sandwiches have filling,
and your deductions be... diamond quality.
No actual diamonds were harmed in the setting of this sudoku.
♫ Thank you, Logic Masters Germany! You've been a wonderful audience. ♫

Solution code: row 4 no spaces

Last changed on on 14. August 2026, 22:26
Solved by SKORP17, Starlight, PierreTombal, Gunkan, sanabas
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Comments

yesterday, 13:18 by sanabas
Quick & easy

on 16. August 2026, 11:50 by Gunkan
Really nice straightforward puzzle

on 14. August 2026, 22:25 by JamesCullum
capitalised digit in rule 4 to make it clearer that Region sum lines use DIGITs and not VALUEs

Last changed on 14. August 2026, 22:28

on 14. August 2026, 22:24 by Starlight
I think it just needs to be made more clear that the sum lines are digit sum lines so don't use "values" when in an arrow bulb. It does say they use digit sum but I can see the confusion and I did miss that at first.

It's a great puzzle though and I loved solving it.

Edit (James) Thank you for your feedback, totally agree, DIGIT is now bold and capitalised :)

Last changed on 14. August 2026, 22:57

on 14. August 2026, 22:00 by PierreTombal
Sadly, the rules are unclear at least with respect to r4c5. Are we meant to use the digit or the value for the region sum? Am I at least correct in understanding that for the purpose of r7c5, we are meant to use the digit in r7c7 and not its value?

Edit: (James) I have changed the rules to make it clearer! Thank you for feedback

Difficulty:4
Rating:N/A
Solved:5 times
Observed:0 times
ID:000UCS
Variant combination
Sudoku, Arrows (Variant), Region Sum Lines (Variant), Sandwich (Variant)

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Solution code:

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