The cards are similar to Bakugan gaming/trading cards. You can collect and trade and play a game with them where you attack and defend. While the rules are similar, the cards are much different. They take things to the next level of cool. The cards themselves are really neat. They have SpinMasters Blast3D technology that makes them look 3D and they appear to move when you move the card. But the best part is that instead of having to keep track of the attack and defense the transparent parts of the cards do it for you. As you stack them they track your health and damage points.
You can check out the Redakai cards on their website.