This is what BillyBob tells us about the new Card Game:
Playing the Card-Jitsu game will start you on the path of your ninja training. The more you play, the closer you'll get to mastering the game and discovering what being a ninja in Club Penguin is all about. When you go to The Dojo, talk to the Sensei and he'll give you a deck of cards to use. There are three modes of play:
Friend Mode: You can have friendly competition with other penguins by clicking on the blue mats inside The Dojo. You'll gain some experience points through this mode.
Competition Mode: The Sensei will match you with another player of similar skill level. You'll gain the most experience points in this mode of play.
Sensei Mode: You can challenge the Sensei at any belt level, but when you beat him at the black belt level (level 9), you'll be rewarded with special online items.
Don't forget that if you have the new Club Penguin Trading Cards, you can click on the Unlock Items Online icon to enter your unique code. It will enhance your online game play. And if you need help with the game, you can go to talk to the Sensei inside The Dojo.
THANKS! BillyBob an Club Penguin Team for this information you are ALL GREAT!