Easy Chaos Construction Sudoku

Irregular region boundaries are deduced during the solve. The grid's own logic reveals where the boxes lie.

Easy Medium Hard Expert

New to Chaos Construction Sudoku? Trace the thick borders to find nine irregular regions — each must hold 1–9. Start here.

5
7
1
4
2
1
6
7
9
6
3
7
8
5
4
3
7
4
3
5
8
4
1
2
8
4
7
3
4
9
2
4
1
7
2
9
8
5
Thick borders separate different regions. Deduce the 9 regions as you solve.
Mistakes
0/3
Score
-
Time
00:00
Try Medium Chaos Construction →
Progress0%

What is Chaos Construction?

Difficulty
★★★★☆
4/5
Constraint Type
Hidden Irregular Regions
Typical Givens
24–32
Avg. Solve (Easy)
12 min

Solving Techniques for Easy Level

Technique Description Level
Border Reading Thick borders separate cells in different regions. Cells without thick borders between them are in the same region. Map connected groups first. Beginner

Ready to go deeper? Try Medium Chaos Construction to unlock Intermediate techniques.

Techniques to Master at Easy

  • Notes in Sudoku — Until regions are mapped you can only trust rows and columns — keep candidate notes based on line logic alone, and annotate region borders separately as you deduce them.
  • Last Remaining Cell technique — Row and column scans still work at full strength while regions are unknown — a digit with one legal cell in its row is safe to place and then doubles as a region-boundary clue.

Average Solve Time by Difficulty

Easy
12 min
Medium
26 min
Hard
50 min
Expert
80 min
Want a full walkthrough of rules, strategies, and solving steps? How to Play Chaos Construction →

Related Variants

Jigsaw Sudoku

The visible-region version of what you solve here — practise pure jigsaw logic without the border deduction.

Samurai Sudoku

Another heavyweight: less meta-deduction, more scale, with five grids trading information through shared boxes.

Clone Sudoku

Also about grid structure carrying information — twin regions that must hold identical digit layouts.

Frequently Asked Questions — Easy Chaos Construction Sudoku

What is Chaos Construction Sudoku?
Chaos Construction Sudoku is a variant where the nine regions are irregular, not the standard 3×3 boxes. Thick border lines show where each region ends, but the regions are not color-coded — you have to deduce them from the borders and the standard row and column rules.
How do I read the thick borders in Chaos Construction?
A thick border between two adjacent cells means those cells belong to different regions. A thin border (or no special border) means both cells are in the same region. Trace the thick borders to work out the exact shape of each of the nine irregular regions.
Do standard Sudoku rules still apply in Chaos Construction?
Yes. Every row and every column must still contain the digits 1–9 exactly once. The extra rule is that each irregular region must also contain 1–9 exactly once, just like the standard 3×3 boxes.
What is the easiest way to start an easy Chaos Construction puzzle?
Look for cells that are heavily constrained by their row, column, and the region they belong to. On easy, some regions are nearly filled or isolated, making the first placements straightforward. Identify small regions (3–4 cells) first — fewer cells means fewer possibilities.
How is Chaos Construction different from Jigsaw Sudoku?
Both variants use irregular regions. Jigsaw Sudoku typically uses color or shading to show which cells belong to which region. Chaos Construction uses only thick border lines, making it harder to visually identify regions at a glance and requiring more active deduction.

More questions? See the full Chaos Construction Sudoku guide.