Su Do Ku is a puuzle that makes you addicted. This is a dialectic game. You do not need to be mathematics genius. There are simple rules. You can choose level of game. There are 81 squares. You are going to put numbers from 1 to 9. Every number can be used once at blocks that has formed 9 squares. Every line and every column must have numbers from 1 to 9. Do not use number twice in the same line and columns. Have a good time..