Logic Masters Deutschland e.V.

Play on f-puzzles

Play on CTC

Watch Simon solve it!

Please remember to leave a rating! It is difficult, so I've left 5 hints that can be revealed at the bottom of this page!

- Normal sudoku rules apply.
- Disjoint groups rules apply; i.e. digits must appear in each position within a box exactly once.
- Antiknight rules apply; i.e. cells a knight's move apart (in chess) cannot contain the same digit.
- Negative diagonal rules apply; i.e. digits cannot repeat along the negative diagonal shown.
- Arrow rules apply; i.e. digits along an arrow must add up to the number in the attached circle.



Hint #1 (Highlight text to reveal):

Think about set theory! Can you find 18 seemingly unrelated cells that must be 2 sets of 1-9 and therefore sum to 90? It's useful to highlight them!

Hint #2 (Highlight text to reveal):

What happens if you put anything less than 9 in r6c3? And then anything less than 8 and 9 in r1c7 and r4c7?

Hint #3 (Highlight text to reveal):

You must put 2 of every digit in your highlighted region, and some digits don't have many potential homes, so think about how to distribute them.

Hint #4 (Highlight text to reveal):

My absolute favourite part of the puzzle... Really think about the options for r6c6 and r7c7!

Hint #5 (Highlight text to reveal):

No more particularly difficult party tricks, just keep scanning and remembering all the restrictions in the rules and you'll get there!

Good luck!