David L. Hoyt's Tic-Tac-Doku

A new twist on 2 classic puzzles!

Puzzle master David L. Hoyt presents Tic-Tac-Doku, an exciting sudoku variant played with only X's and O's. Based on tic-tac-toe rules, this innovative version of sudoku presents an irresistible invitation to put the problem-solving parts of your brain to work in a whole new way. Included here are easy, medium, and hard puzzles, as well as quick-playing Tic-Tac-Doku Express ”cubes.” Whenever you're ready for a logic-puzzle challenge, reach for Tic-Tac-Doku to keep your mind sharp!