D&uuml;-KO Game D-KO brilliantly transforms Sudoku from a solitary puzzle into a board game that up to 9 friends can play It's Sudoku gone social! An interactive, self-checking Sudoku game that sharpens concentration improves critical thinking skills and provides loads of fun Allows traditional solitaire Sudoko play, yet D-KO ramps up the fun with competitive and cooperative play! 5 GAMES IN ONE FOR EVERYONE!!!