PUZZLE CONNOISSEUR'S CLUB

About Noughts and Crosses Puzzles

Noughts and Crosses Puzzle Rules

The rules of Noughts and Crosses Puzzles are as follows:

• Place an equal number of noughts and crosses in each row and column of the grid
• No symbol can appear in more than two consecutive squares of a row/column
• No row can repeat itself, and no column can repeat itself

Here is an image of the start position of a noughts and crosses puzzle:

The first rule means that, for instance, on an 8x8 grid such as the puzzle shown here, there are four noughts (0) and four crosses (X) to be placed in each row and column of the grid. The second rule is fairly self-explanatory, and means that a run of 000 or XXX in consecutive squares is banned. The third rule is perhaps the hardest to grasp, but simply means that the makeup of each row is unique, and each column is unique. Thus if column one contains 0X0X0X0X then no other column can contain the same sequence.

If you'd like to see the rules explained using the sample grid above, then this video should prove of interest:

Play A Noughts and Crosses Puzzle

You may have come across this puzzle type under various names such as binary puzzle and kurosu; there are various other names too. However if you've not played it before, you might like to have a go at a puzzle with our Online Noughts and Crosses Puzzle Player

If you enjoy this puzzle type, you can join our online Puzzle Connoisseur's Club for £12 or $17 a year and play a new Noughts and Crosses Puzzle puzzle every day of the year, together with many other fun and interesting logic puzzles.

Noughts and Crosses Puzzle Solving Tips and Techniques

If you join our puzzle club above, you'll be able to play a new noughts and crosses puzzle every day of the year. None of the puzzles will ever require guessing or have multiple solutions, but you'll need to be good at spotting the patterns that will help you solve the puzzles. Here are some solving tips and techniques for you:

• Start solving by looking for pairs of the same symbol placed consecutive in the grid, for instance anywhere you see XX or 00 in the grid you can place the other symbol either end, thus if you see XX in the middle of a row, you can put the 0s in at either end to make 0XX0


• Next, look for places where you have the same symbol with a single blank square between them, such as 0?0 or X?X, with the question mark representing a blank square. Where you see this, you can put the other symbol in the blank square, thus 0X0 or X0X in the example here. The alternative would be to have the same symbol in three consecutive squares, which would break the rules


• Remember that when you are filling in a row or column, you must place an equal number of each symbol. Thus in an 8x8 puzzle, there are four Xs and four 0s. Let's imagine our row looks like this, again with ? representing a blank square: ?XX0X0X?

  We can complete the row by placing 0s where the question marks are. That's because, on counting the number of each symbol in the region, we can see there are already four X's in the row. We know that is the maximum number allowed in a row in an 8x8 grid, and therefore the remaining blanks must contain 0s.