Hypersudoku

Hypersudoku, also known as "hyper-sudoku", "hyper sudoku", "NRC sudoku", "windoku" or four square sudoku" is another variant of sudoku.

How to play hypersudoku

This game requires no mathematics skills. It is purely a logic game with the only prerequisite to be able to count to nine.

Hypersudoku Rules

The rules for playing hypersudoku are very simple:
# All rows must have all the numbers from 1 - 9 in them (none can be repeated). There are 9 rows in the game.
# All columns must have all the numbers from 1 - 9 in them (none can be repeated). There are 9 columns in the game.
# All 3x3 squares must have all the numbers from 1 - 9 in them (none can be repeated). There are 13 squares in the game. There are the 9 underlying 3x3 squares (divided by the dark blue lines) and the 4 overlaying (shown in light blue in the following diagrams).

Hypersudoku logic

New Game Hypersudoku is a game of logic. The following is a brief explanation of the logic necessary to develop your strategies for the game of hypersudoku. As you will see in the following diagrams there are many starting points for the game in figure 1. This is a fairly typical layout for an easy level hypersudoku game. These are only a few of the many starting points in this particular game.
Example 1 Looking at the center square we can see that column 4 has a 9 at the bottom(circled in red). This means that a nine can not appear again in this column. Column 5 also has a 9 in it. This time up in the top middle square. This leaves column 6 as the only option for a 9 to appear in the center square. As 6 and 4 take up 2 of the 3 squares available, there is only one square left. This is the one with the blue tick in it. This square will contain the 9.
Example 2 In figure 3 if we look at the top right square, we can see that rows 2 and 3 already have a 5 (circled in red) in them. This leaves the square with the blue tick as the only possibility for a 5 in this square.
Example 3 Again the same starting game, but this time looking at the middle right square. Rows 4 and 6 contain a 4 already, leaving only row 3. As the other 2 squares already contain numbers, the square with the blue tick is the only square that can contain a 4.
Example 4 In figure 5 we can see that the top row and third row already have a 6 in them. The sixth column also has a 6 in it. This leaves the square with the blue tick as the only square that could contain a 6 in this block.
Example 5 If we look at the bottom center square we can see that columns 5 and 6 both contain a 5 (circled in red). This leaves only one square in this block that can contain a 5.(square with blue tick)
Example 6 In figure 7 we see that column 1 and 2 have a 2 in them already. Also note that row 5 has a 2 in it. (circled in red) Again this only leaves the square with the blue tick in it as the only possible square in this block that could contain a 2.
Example 7 If we look at the top right blue square, it has to have a nine in it. The top corner square (in red) that overlaps the blue square already has a nine in it (circled in red). The middle top square that also overlaps the blue square has a nine already in it (circled in red). The middle right-hand square also has a nine in it which only leaves the square with the blue tick as the only possible square for nine to go in in the top right blue square. As you can see the logic of the overlapping squares is quite helpful for solving these puzzles.
Example 8 In this example if we look at the bottom left blue square, it has to have a six in it. The bottom corner square (in red) that overlaps the blue square already has a six in it (circled in red). This six is also the only six that can exist in this column so that eliminates the top middle blue square (marked with red cross) .The middle bottom square that also overlaps the blue square has a six already in it (circled in red). This only leaves the square with the blue tick as the only possible square for six to go in in the bottom right blue square. As you can see the logic of the overlapping squares is quite helpful for solving these puzzles.

These are not the only starting moves for this particular game.

Online play

* [http://www.hypersudoku.com hypersudoku.com] . Online playable hyper-sudoku game.
* [http://www.sudoku-space.de/hyper-sudoku/ www.sudoku-space.de/hyper-sudoku/] Online playable and as PDF for printing.