About Gridoku™

Gridoku is a logic puzzle that is based on the logical placement of letters within a square grid. An online game of logic, Gridoku does not require any calculation nor any advanced technical skills; all that is needed are practice, logical thinking, and concentration.

How do you play Gridoku?

There is an empty square grid. There are five levels of difficulty – Easy (3x3 grid); Medium (4x4 grid); Hard (5x5 grid); Expert (6x6 grid) and Evil (7x7 grid). The square grid is always initially empty.

On the keyboard, you will see a certain number of letters, say, A, B and C. The number of letters is always less than or equal to the number of empty cells in each row or column, with a minimum of 3 letters. For example, in a 4x4 Gridoku, the number of letters may be 3 or 4. If the number of letters is less than the number of cells in each row or column, then each row and column will have a certain number of empty cells. In any event, each letter must occur once and only once in each row and column.

There are certain CLUES given outside the square grid. The more the number of clues, easier the puzzle. The clue must match the letter that is closest to it in that row or column. For example, if there is a C as a clue for a certain column on its top, than in that column, C must be the first letter from the top (it may or may not be preceded by one or more empty cells) – but an A or a B cannot appear in that column prior to a C from the top.

One cell can contain only one letter – it may be empty if the number of the letters in the puzzle is less than the number of cells in that row or column.

Playing Tips:

Gridoku is a fun and addictive puzzle once you get the hang of it. It is not always easy, but the trick is never to give up. Keep trying and you will get a hang of it. Start with the lower levels of difficulty and then move up in the levels of difficulty.

Learning to play Gridoku can be a bit intimidating in the beginning. So, if you are a complete beginner, here are a few tips that you can use to improve your skills.

• Tip #1: Start with the clues outside those rows and columns. On the cells right next to it, you can pencil in the possibilities. For example, if there is a C on the top of a certain column as a clue, then the first cell from the top in that column can only be a C and nothing else (or it can be empty). Then logically eliminate all the other possibilities in other cells as you look at the whole grid.
• Tip #2: Let us say that you are playing a 4x4 grid and there are three (3) letters A, B and C to be placed in the grid. And let’s say, for a certain column, you have a clue C on the top. There are four cells in that column and 3 letters. The letters in that column must have C at the very top. So, C can only appear either in the first or the second cells of that column from the top. It cannot occur in the 3 rd or the 4 th cells from the top in that column. Thus, you have lowered the number of possible locations and you can work through the puzzle.

Now that you know a little more about Gridoku, go ahead and jump right in. The more you play, the better and smarter you will get.

About MATHinkCO:

MATHinkCo is a privately owned company, started by 3 high school and middle school brothers who are committed to developing exciting content in math and logical thinking to promote the love for puzzles and math games online. This website and the associated mobile apps are all owned by MATHinkCo LLC.
You can find more information on MATHinkCo at www.mathinkco.com.