Sudoku Gattai
Sudoku Gattai is a sudoku variation with three overlapping sudoku grids. Here’s an example:
Note: In Japanese, Gattai is a generic name for different types of overlapping sudokus. We’ve adopted the name for this specific sudoku variation, but you can also encounter names like Gattai-3, Gattai-8, Gattai-21, where the number indicates how many overlapping grids there are.
Understanding Sudoku Gattai
In this article we’ll show you tips for gattai sudoku. Gattai sudoku strategies include all the regular sudoku strategies, but the areas where grids overlap make it more complex. These strategies will work for easy sudokus and for challenging gattai sudoku. We’ll use colors to analyze the overlapping grids:
The layout of the overlapping grids in this sudoku may make it look very complicated. There are three grids: Green (1), Yellow (2) and Red (3). Each grid can be solved like a regular sudoku, but you may get stuck if you try to solve just one grid at a time.
We’ve indicated the overlapping regions with blue squares and a letter:
- Light blue (A) is part of two different grids – Either green and red (3 areas), yellow and green (1 area) and yellow and red (1 area)
- Blue (B) is part of three overlapping grids (green, yellow and red
Six different regions that have overlap between the grids. In the following paragraphs we’ll show you how to apply the clues in the different areas
How to solve Sudoku Gattai puzzles
One of the basic solving techniques for sudoku gattai is to mark the different grids with a colored pencil, to help you see the “line of sight” or the “neighbors” of each clue.
Solving Sudoku Gattai – Example 1
In this first example you see a clue (the number “8”) that is part of the green grid (1) at the top, but not part of the other grids.
This “8” can only be ‘seen’ by cells in the same grid (green grid 1). The green arrows show which cells are direct ‘neighbors’ of the “8”. These cells cannot contain the “8”.
(Note: we didn’t indicate the small 3×3 region that surrounds the “8”. The usual Sudoku rules apply here.
Solving Sudoku Gattai – Example 2
In this example you can see the “7” that’s part of the green grid (1) and the left (yellow) grid (2). The “7” has direct neighbors in both grids.
The green lines with arrows indicted the neighbors in the green grid (1). The yellow lines indicate the neighbors in the yellow grid (2). In all these cells, the “7” cannot be placed, because it’s ‘visible’ from these cells.
Solving Sudoku Gattai – Example 3
In this example we have chosen the “6” that is part of three different grids: the green grid (1), the yellow grid (2) and the red grid (3).
That means that the “6” cannot appear in the same row in the green grid (1), the yellow grid (2) or the red grid (3), and the “6” can also not appear in the same column in the . green grid (1), the yellow grid (2) or the red grid (3). We’ve indicated this with lines in the color of the grids.
Additionally, the “6” cannot occur anywhere else in the small 3×3 region, which is the common sudoku rule.
The three images below show the colored arrows for each of the three grids individually:
Create Sudoku Gattai Puzzles
We hope this article helps you with mastering sudoku gattai puzzles. If you need more puzzles, Sudoku Gattai is part of our Sudoku Multidokus 2 module in Puzzle Maker Pro.
You can test drive this module in our Free Demo version of Puzzle Maker Pro.
An overview of all modules and sudoku types can be found on the Sudoku Products page.
