Word and Letter Sudoku
Mix up your sudoku game with a few letters. These word sudoku puzzles might be just the extra challenge you are looking for.
Word Sudoku Rules
These are played just like a regular sudoku, except that each of the digits is replaced by a unique letter. Each of the nine rows and columns, as well as each of the nine subregions, must contain one and only one of each of the nine letters.
All of these puzzles are in PDF format, which you can print for free. The solutions are given on the second page of the PDF.