Book excerpt: The Milton Bradley game of YAHTZEE, with its five dice and special score sheets, sold in the millions last year. Now experienced players and newcomers alike can enjoy the game anywhere (in a moving car, for instance), without worrying about losing any of the dice. It's an ingenious use of the scratch-off concept made familiar by lottery games, and which has made a big hit in books such as "Scratch & Solve(R) Hangman." The object of YAHTZEE is to get high-ranking combinations of the dice, similar to poker hands. With this version, competitors "roll" by scratching. Using two copies of the book, readers can complete in exciting head-to-head competitions, where both players start each round with the same roll.