Knight Imposters
(Published on 22. March 2026, 19:03 by CarnacTheMagnificent)
King Sudoku VII has summoned you to his castle to investigate 81 knights. The king has learned the following:
Of the 81 knights, 18 of them are imposters
Your objective:
Identify and kick the imposters out of the king's castle
Rules:
-
Normal Sudoku rules apply
- ie., put the digits 1-9 in every row, column, and 3x3 box
-
Killer Cages
- Digits in a cage sum to the given number; No digit can repeat in cages
-
XV rule set
- An "X" between cells indicates that the two cells must sum to 10; not all "X"'s are given
- A "V" between cells indicates that the two cells must sum to 5; not all "V"'s are given
-
German Whisper Lines
- Digits along a green line must differ by at least 5
-
Quadruples
- The four digits in the circle must be in the cells where the circle touches
-
Kropki Dots
- Black dots
- Cells separated by a black dot indicate that one digit is double the other; not all black dots are given
- White dots
- Cells separated by a white dot indicate that the digits are consecutive; not all white dots are given
(Warning: Follow this next rule at your own risk) - Black dots
-
Anti-Knight
- Cells separated by a knight’s move in chess cannot contain the same digit EXCEPT the imposter digits
- Imposter Rules
- Every imposter sees at least one other imposter of the same value within a knights move
- Orthogonal 67 pairs are NOT imposters
- Why? Because all imposters DESPISE and AVOID 67 pairs
- If there is an orthogonal 67 pair, in any order, the cells surrounding the 67 pair are NOT imposters (up to 10 cells maximum)
- Of the 18 imposters:
- 3 "guard" the castle wall perimeter (Row 1, Column 1, Row 9, and Column 9)
- 8 are prison "guards" (in cages)
- 6 whisper in German
- 1 has infiltrated the King's circle of 4 advisors (Box 2)
-
Helpful Advice
- Recommend coloring imposter and non-imposter digits
- If you identify all imposters in one constraint, the remaining digits are NOT imposters
- For example, if you find all 6 imposters on German Whisper lines, the remaining digits on German Whisper lines are NOT imposters
- Deadly patterns can be resolved (if any)
Solution code: The sum of all imposter digits
Comments
on 23. March 2026, 22:22 by dzamie
This puzzle is alright, but poorly named. Knight and impostor related rules get used exactly once each, right at the end, and the "where each impostor is" hint is utterly useless.
To be perfectly honest, it seems like you made a pretty fun puzzle with more standard rules, and then just added the impostor knight thing to get rid of a deadly pattern.
on 23. March 2026, 16:36 by VitP
out the airlock with the imposters, and everyone who downvoted this puzzle.
there are TWO separate puzzles here: the sudoku, and locating the imposters.
the sudoku solves very easily (level 1), completely ignoring all the imposter rules, except for the final deadly pattern, which locates TWO of the imposters.
on 23. March 2026, 03:10 by CarnacTheMagnificent
@itsid: I incorporated your version of the first imposter rule as that makes more sense. Thanks for the comment and feedback.
on 23. March 2026, 02:34 by itsid
IDK somehow the first imposter rule threw me off...
a lingual issue I guess;
but I think it means every imposter sees at leat one other imposter of the same value within a knights move.
Anyways, nice puzzle, thank you
on 23. March 2026, 01:29 by Hari
Really fun construction and well described instructions!
on 22. March 2026, 22:15 by marajade
This was fun, thank you for setting it!
on 22. March 2026, 20:09 by Guillem98
the imposter rules is just needed for one digit, interesting
