Multi Sudoku is one of the challenging but at the same time, interesting sudoku variants that have been developed in the logical world of puzzles. It is a sudoku puzzle that consists of two or more sudoku grids. The unique part of multi sudoku is that certain region(s) of the sudoku grids are overlapping each other in various configurations. The grids may be a standard sudoku or a mix of other sudoku variants.
How Do You Play Multi Sudoku?
The rules for playing Multi Sudoku are just simple. Like in classic sudoku, place numbers 1 to 9 in each row, column, and 3×3 box exactly once. In addition, the numbers that you have placed in the overlapping areas must satisfy all the given sudoku grids. To start with, let me show you a simple multi sudoku with two overlapping classic sudoku grids.

The red boxes in the puzzle above are called the overlapped regions. In answering this multi sudoku puzzle, you can start finding the first number at the overlapping regions since you will have two (in this case) or more sudoku grids to help you find clues for that first number. For example, the number 9 in Row 8 of the puzzle (the one with the ref font) was placed at that exact cell through a cross-hatching technique from the given number 9 in both sudoku grids. Moreover, do not panic if you can’t find any single candidate in the overlapping regions because you can still start with the regions that are not intersecting.
Most Popular Multi Sudoku: Samurai Sudoku
Now let’s move forward to the most popular multi sudoku, which is called samurai sudoku. This type of multi sudoku is a puzzle consisting of five overlapping sudoku grids. Yes, five. These five grids overlap to form an X-like shape. I know that the size of the grids sometimes creates a scare. At first glance, Samurai Sudoku appears complex and formidable, with five classic sudoku grids, four overlapping corners, and 369 cells in total, provoking your sudoku skills. As obvious as it seems, this multi sudoku does take longer to crack, but the rules are the same as classic sudoku. The only glaring differences are the four overlapping regions to consider.

Tips to Solve Faster Multi Sudoku
To better appreciate this kind of multi sudoku, here are some suggestions or tips to solve faster. The five sudoku grids, as labeled in the picture above, can be solved independently of each other. The first step is to avoid trying to solve or look at this multi sudoku in its entirety. Work with one classic sudoku grid first and then move to the next one, and so on. Find all cells with the single candidate that you can find using different sudoku techniques in sudoku grids 1-4 before moving on to the last grid because, in most cases, grid 5, or the grid where the overlapping occurs, is the hardest to solve. So it will be more time intensive, and at the same time, you’ll get frustrated at the very start if you begin solving in multi sudoku grid 5. It will throw you off, especially if you compete in a sudoku competition. Still, you can encounter multi sudoku puzzles where you can easily get your first number at grid 5. It all depends on the difficulty of the puzzle. On the other hand, the shared four corners (those at the red squares) are solved by considering both overlapping grids. For example, the overlapping region at the top left must be solved by taking into account the numbers given in grids 1 and 5. Once you’re able to solve the overlapped region, the multi sudoku becomes quite easy.
As mentioned before, multi sudoku can be a mix of other sudoku variants. The commonly known sudoku variants that usually appear in multi sudoku are Diagonal Sudoku, Irregular Sudoku, and Windoku. Although I will not delve into this type of samurai sudoku in this article, I still want to share that this variant exists. And for it to be solved, you have to know the rules and strategies of each variant. Stay tuned to our website, as future sudoku articles will explain these sudoku variants.
Summing Up Multi Sudoku
To sum up all the things about multi sudoku, you should realize by now that the size of the grid should not scare you. Instead, you must feel challenged and eager because solving multi sudoku is truly very satisfying.