Mojidoku is a variant of Sudoku that uses letters.
The game of Mojidoku consists of completing a square grid of 9 rows and 9 columns with 9 regions of 9 boxes partially filled, with letters from A to I. The same letter can appear only once on a line, a column and an inner square of the grid. To help you, you can write draft letters in each box. 4 levels of difficulty are available: easy, medium, hard and expert. There is 40 grids per level of difficulty. The name Mojidoku comes from the Japanese Moji (letter) Doku (unique). This game is identical to Sudoko (Su = number) but the numbers are replaced by letters. The Mojidoku is very appreciated by those who prefer the letters to the numbers as for example the amateurs of crossword puzzles.