There are only 2 types of this puzzle based on Shape and Size. Each and every Dominosa puzzle is a combination of these 2 types. Why ? Because every puzzle has Shape and Size.

Shape – the most popular is of course rectangular shape which you can see in every publication. They are never in the shape of square. Count rows and columns for yourself. Some authors tries to make fancy looking puzzles, and frankly, I am trying to develop many of these. It is a field that opens a door to imagination, and everybody can try to create something unique.

Size – physical size of Dominosa depends on the size of domino set used. The smallest size that makes sense to use is 3×3 set. It is 10 domino tiles starting with 0-0 and ending with double 3-3. And it follows that we have 20 numbers arranged in the field of size 4×5. Below is an example:

Dominosa was developed by O. S. Adler in 1874. It was patented by Richard Osa (pseudonym for O. S. Adler) in Germany in 1893 as German Reichs Patent No. 71539 and published in 1894 under the name of “Dominosa”, combining ‘Domino’ with Adler’s initials. It later appeared in 1912 in a domino puzzle book , co-authored by Fritz Jahn [4].

I love to play Dominosa . That is the fact. But it wasn’t always like this. It wasn’t love from the first sight. Actually I hated this game ! After finding several tiles I was clueless on what to do next. Frustration was my normal state. Until I told to myself I needed to try harder and was able to solve my first 6×6 Dominosa. I found real beauty in this simple game discovering more and more ways to solve these puzzles. And logics is the only tool one needs. Period. I do not use word technique but way to solve. This is not Sudoku, what frustrates me a lot. And I call it Sadistoku.

First of all, Dominosa is a completely different game that Sudoku. It really surprizes me when some authors call this game Sudoku Dominosa, or they say: If you liked Sudoku, you WILL like Dominosa. It sounds to me like marketing or comercial talk. Dominosa has no restriction regarding the placements of digits. NONE ! Playing area can be of any shape (check my other posts), no columns, rows and blocks have to add to certain sum, multiple, the same digits can be in the same columns and rows etc. Secondly, there is no easier game to be created by hand. Try it with Sudoku. And good luck !Thirdly, solving Dominosa is real fun. No sophisticated technics are needed, only keen eye and some deductive skills (which everybody can develop). More later.