Using letters instead of numbers is an obvious way of creating a sudoku variant. But surprisingly, in my sudoku research that I conducted AFTER I created this **Alphabet Soup Sudoku**, I have not come across a letter sudoku that uses the whole alphabet. Surprisingly because why would you use letters if your are not going to use all of them? I saw one that came close. It used 25 letters (A 25×25 grid allows the creator to subdivide the sudoku to 5×5 subregions. While that makes sense, leaving a letter out does not.)

Most of the letter sudoku I came across use 9 letters and are the classic sudoku 9×9 grid form. This form make great sense if you are using numbers because there are 9 single digit natural numbers (1-9). This allows the sudoku to be subdivided into nine 3×3 subregions. It is all nice and neat and beautiful. But using 9 letters is silly and totally pointless. It is bad design.

But I have an idea that would further the **Alphabet Soup Sudoku**. (Once again, All Rights Reserved. I want Konokopia to be the first one to publish these new type of sudoku.) The idea is to incorporate isograms into a letter sudoku. An isogram is a word or phrase without a repeated letter in it. For example, the following words are isograms: trapesoid, nightmare, artichoke, boyfriend, introduce.

I intend to try using isograms in the **Alphabet Soup Sudoku** in two ways. One way is to put in as many different isograms into it as I can. Thus the sudoku also becomes a kind of word search.

The other way of using isograms in a sudoku is to create different sudoku puzzles from single specific isograms and only use the letters that appear in that isogram in the sudoku. I call this the **Isogram Sudoku** (**Word Sudoku**?). For example, a 9×9 grid letter sudoku that uses the letters A, E, G, H, I, M, N, R, T: the **Nightmare Sudoku**.

This is a beautiful variant of the letter sudoku because it is no longer arbitrary. The isogram determines the size of the puzzle and the specific letters that are used. The **Isogram Sudoku** is now just as nice and neat as the 9-grid numerical sudoku. But it adds the poetry of words and eliminates the "genericness" of the numerical sudoku.

My next sudoku kids puzzle book will use isograms to create different sized letter sudoku puzzles. Maybe the words of each sudoku will form a sentence, a message, of some kind to tie all the sudoku puzzles together. I don't know yet, but I am very excited by the idea. Right now, I am collecting as many isograms as I can so that I have a large group of words to choose from to make my sudoku puzzles. I am sure, that the words will give me some additional ideas as to how to develop this **Word Sudoku** book.