Logic Masters Deutschland e.V.

Duel Training (Chaos Construction)

(Published on 8. September 2026, 16:17 by Mad-Tyas)

As all my previous 9x9 puzzles using this ruleset have been rated 5/5 stars for difficulty, my aim was to design an easier 9x9 puzzle. However, it is proving quite difficult to design a truly accessible puzzle of this size using this ruleset. I hope I have at least managed to make it a little easier than the previous puzzles in the series.

Sudoku on:
SudokuPad


Rules:

Chaos Construction: The grid has to be divided into nine regions of orthogonally connected cells. Each row, column and region has to contain the digits 1-9 once each.

Duels: At each region border, a duel takes place between the adjacent regions. To determine the outcome, for both sides the contiguous sequences of cells extending perpendicular from the region border to the next region border or the edge of the grid are compared. The region whose sequence of cells has the higher sum of digits wins the duel. An award of X points for the winning region and a penalty of -X points for the defeated region are taken by the cells touching the region border where the duel takes place. X equals the number of cells in the sequence of the defeated region. If the sum in both sequences is equal it's a tie and no points are awarded.

Clues:
- An arrow between cells marks a region border and points to the defeated region in the duel at that border. A diamond marks a region border where the outcome of the duel is a tie. Not all arrows and diamonds are necessarily given. A black line between cells marks a region border but the outcome of the duel isn't given.
- A small number in the bottom-right corner of a cell gives the total points this cell wins/loses in the duels at its up to 3 region borders.
- The cell with a grey circle has to contain an odd digit.

Have fun solving!


Example: This is the solution to a 5x5 example puzzle. For the arrows shown, the points gained or lost are indicated to illustrate how duels work. For example, the central cell loses the duel at its left-hand region border (sum of 5 [4+1] is less than sum of 8 [5+3]) and receives 2 minus points, as the sequence of cells in the losing region (blue) consists of 2 cells. The cell wins the duel at its upper region border (4 against 2) and gains 1 positive point for this, as the losing region (green) contributes only one cell to the duel. At the lower region border, the result is a tie (4 = 3 + 1). This results in a total score of -2 + 1 + 0 = -1 for the cell in question.

Solution code: The 9 digits from column 8 (top-to-bottom) separated by (+) for borders between regions


Solved by marcmees, sehringdipity, DarthV13, gdc, Jesper, bansalsaab, lsw770770, emoney1374, haoju, lmdemasi, Isael, rmm466ss, Bootenks, jkuo7, War, BlazingSnow, zakkai, Mr_tn, misko, han233ing
Full list

Comments

on 22. September 2026, 20:39 by War
Reduced difficulty accomplished

on 9. September 2026, 03:45 by emoney1374
Fun puzzle!

Last changed on 8. September 2026, 19:01

on 8. September 2026, 18:53 by marcmees
3* imo but certainly as interesting as the harder ones. Mission accomplished. Thanks

Difficulty:5
Rating:98 %
Solved:20 times
Observed:1 times
ID:000URW

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