Su Doku, "the crossword without words," comes with a warning: it is seriously addictive. You don't need to be a mathematical genius to solve these puzzles; it is simply a question of logic and a little patience. Here is a giantcollection of puzzles from New York Post Su Doku 1, 2, and 3 arranged according to difficulty, starting with the easiest and ending with the fiendishly difficult.