Logic Masters Deutschland e.V.

A Duel at Christmas

(Eingestellt am 13. Januar 2024, 13:10 Uhr von The Book Wyrm)

This puzze was originally created as a gift for Playmaker during the 2023 Secret Santa exchange on the CtC discord, and has been posted here with his permission.


  • Normal sudoku rules apply: place the digits 1-9 once each in every row, column and region.
  • Divide the digits into two teams. Each team contains 4 digits total, including: 2 high digits, 2 low digits, 2 even digits, and 2 odd digits.

    5 is a double agent; it may play for either team (though only one team at a time).

  • All digits of one team are orthogonally connected.

    All digits of the other team are orthogonally connected to the edge.

  • Digits along an arrow sum to the digit in the circle. Only digits belonging to the opposite team as the digit in the circle contribute to the sum.

  • Clues outside the grid are either X-sums or numbered rooms clues, to be determined by the solver.

    X-sums: Clues give the sum of the first X digits in that row/column, where X is the first digit in that row/column. Only digits belonging to the opposite team as the first digit contribute to the sum.

    Numbered rooms: Clues outside of the grid indicate the digit which has to be placed in the Nth cell in that row/column, where N is first digit in that row/column. The number indexed must be from a different team to N.

    ? respresents a number from 1-9, and ?? represents a 2-digit number.

Sudokupad link: Click Here

Penpa+ link: Click Here

Lösungscode: Column 5, from top to bottom (9 digits)

Gelöst von Playmaker6174, marcmees, Jasura, zzw, cornish-john, jkuo7, wildbush7
Komplette Liste


am 22. Februar 2024, 20:25 Uhr von wildbush7
Nice, really enjoyed it throughout!

am 15. Januar 2024, 21:36 Uhr von zzw
Really cool idea, and a great execution, lots of fun. Some very tricky bits that I eventually found my way through...

am 15. Januar 2024, 18:21 Uhr von marcmees
very very tricky ... but how well constructed. Amazing puzzle. thanks.

Zuletzt geändert am 14. Januar 2024, 15:11 Uhr

am 13. Januar 2024, 14:23 Uhr von marcmees
Is it correct to say that different 5's may play for different teams ... but once its team has been chosen, it may not change team to fit/ignore an other clue?


Yes, that is correct. Different 5s may be on different teams, however for each 5 in the grid, it counts as only one team for the connectivity and counts as the same team for all clues it affects.

thanks for the reply.

am 13. Januar 2024, 14:17 Uhr von Playmaker6174
I’m very honored and delighted to receive a lovely gift with such a cool (and quite mindtwisting) concept! Took a long while to realize that I’d overlooked an option during certain step (which got me into contradictions in quite a while) but it went nicely again after that. Thanks for this gift! :)

Gelöst:7 mal
Beobachtet:2 mal


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