Logic Masters Deutschland e.V.

Dutch Flat Mates: April Fools' Day

(Published on 1. April 2026, 07:00 by Flinty)

Previous Dutch Flat Mate Puzzles
This has been a weekly series since '18 Oct 23'. Here is a spreadsheet link for all the previous puzzles in the series, which also has a few teasers for upcoming constraints/guest setters in the series (subject to change).
This alternative link offers a limited LMD search for Dutch Flat Mates.

To play the puzzle, please click the image:


Puzzle Link: Click Here

Initial Setter Difficulty: 2-2.5 / 5
(It was VERY tempting to ONLY list the above 'puzzle' as a 5/5.)

Puzzle Pack
With April Fools' Day falling on a Wednesday this year, it felt appropriate to have a little fun with this weeks epsiode. This is a small pack of 6x6 puzzles, using constraints that have appeared before, with a twist!
I really hope you enjoy.

Hint to start

5 in Row 1 cannot have a 1 above it, so must be psuedo satisfied by the clues themselves.

A bit more of a hint / spoiler

In every puzzle, the 5 in Row 1 has been given 2 options - Either with a 1 clue above it, or a 9 clue below it. There are no more shenanigans than that on Flat Mates.
A required logical deduction, is that all the other 5s need real 1s. As such, the 1 in R6 will always appear in the same column as 5 in R1.


Puzzle 1 of 4: Killer
- Normal 6x6 Sudoku rules apply.
- Dutch Flats: Every 5 in the grid must 'somehow' have a '1' directly above it or a '9' directly below it. It may have both, but it doesn't need both.
- Killer Cages: Digits in cages do not repeat and must sum to the indicated totals.

To play the puzzle, please click the image:


Puzzle 2 of 4: Diagonal Outside
- Normal 6x6 Sudoku rules apply.
- Dutch Flats: Every 5 in the grid must 'somehow' have a '1' directly above it or a '9' directly below it. It may have both, but it doesn't need both.
- Diagonal Outside: Clues outside the grid give digits that must appear in the first three cells, exactly once, in the indicated diagonal direction.

To play the puzzle, please click the image:


Puzzle 3 of 4: Renban
- Normal 6x6 Sudoku rules apply.
- Dutch Flats: Every 5 in the grid must 'somehow' have a '1' directly above it or a '9' directly below it. It may have both, but it doesn't need both.
- Renban: Each purple line contains a set of consecutive, non-repeating digits, which can appear in any order.

To play the puzzle, please click the image:


Puzzle 4 of 4: Full File Kropki
- Normal 6x6 Sudoku rules apply.
- Dutch Flats: Every 5 in the grid must 'somehow' have a '1' directly above it or a '9' directly below it. It may have both, but it doesn't need both.
- Full File Kropki:
Clues in a white circle indicate the exact number of white, Difference of 1, Kropki dots in their respective rows and columns.
Clues in a black circle indicate the exact number of black, Ratio 1:2, Kropki dots in their respective rows and columns.

To play the puzzle, please click the image:

Next Week
That's the end of the series I'm afraid, I'm retiring* from setting variant Sudoku.
(*I'm not, this is a terrible/obvious April Fools' attempt)

There will be guest setters the next two weeks!
GoodCity is working on a 'ytiCdooG' puzzle, whilst SennyK makes his series debut with his wonderful German Sums constraint.

Solution code: Puzzle 4 of 4 (Full File Kropki) - Column 2 (6 digits)

Last changed on -

Solved by Crusader175, TheCutmaster, raaaaa, 72kchunshuai, SennyK, tuturitu, NEWS, juggler, damo_89, sorryimLate, Leaving Leaves, OJPS, Yawnus, L00ping007, Dreamy4Vada, mathhead, SweJo, sujoyku, Avron, ... pagedo, Akk1yyy, marcmees, VFRIP, abihummel, Allagem, EmmaMadelief, teuthida, Exigus, clock, MorsBe, Tompzini, pmatos, Drafuf, moss, widjo, macmillan333, richcard, dingledork, Sus, Voidslime, filz
Full list

Comments

Last changed on 1. April 2026, 19:43

on 1. April 2026, 19:42 by Hay-in-needlestack
The first one was tough but after that they luckily got easier.

on 1. April 2026, 16:04 by meiwanmeiliao
最后三道题还好,就第一道太难了,根本无从下手

on 1. April 2026, 16:04 by meiwanmeiliao
最后三道题还好,就第一道太难了,根本无从下手

on 1. April 2026, 16:04 by meiwanmeiliao
找好三道题还好,就第一道太难了,根本无从下手

on 1. April 2026, 16:04 by meiwanmeiliao
找好三道题还好,就第一道太难了,根本无从下手

Last changed on 1. April 2026, 12:30

on 1. April 2026, 12:29 by sujoyku
I had to use the powerful technique of Flinty-liffing more than once in this series. As most beginners probably will not know this mighty approach, this absolutely cannot qualify as Level 1 difficulty. :P
Great puzzle otherwise!

on 1. April 2026, 11:19 by Black_Doom
Gotta admit, the first puzzle defeated me. Don't think I'm good enough for the rest of the pack :(

Last changed on 1. April 2026, 08:59

on 1. April 2026, 08:58 by Martina
I am proud to report that I cracked this in 47:30 ;-)

on 1. April 2026, 08:55 by damo_89
Difficulty 1/4

on 1. April 2026, 08:28 by juggler
Very fun and very approachable!

on 1. April 2026, 07:47 by SennyK
Lovely April Fools' Day idea, I had a lot of fun solving all of those funny puzzles! :-)

Difficulty:2
Rating:96 %
Solved:74 times
Observed:1 times
ID:000RZR

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