I Know... You Don't has five levels of difficulty and it's a great card game for all ages. With a little guessing, and a little deduction, you can crack the code. The goal of the game is to be the first player to get rid of all your cards. Every card played gets you closer to uncovering the pattern. Which card fits the secret rule? Only the Rule Keep knows - thus, I Know...You Don't. Crack the code to uncover the secret rule and win the game!