Card-Jitsu cards are the main feature of the series of Card-Jitsu games. They are special cards, found by Sensei long ago. There are currently 509 different kinds of cards in the game, with a variety of other cards that are not in the game, and only exist in real-life. Each card can be one of six colors, either red, blue, yellow, green, orange, or purple. Each card also has a value, which is a number ranging from 2 to 12. Lastly, cards each have an element, that determine which card wins. If the elements of two played cards are the same, the one with the higher value wins. If both values are the same, the cards are tied.
Card-Jitsu cards can be unlocked with codes from real life cards, and Power Cards can also be bought three at a time (one of each element) for 1500 coins in the Martial Artworks catalog, as of the Dojo's renovation in May 2013. Only members can buy cards from Martial Artworks, and if a player's membership expires, the cards bought from Martial Artworks will not be able to be used until membership is renewed.
List of Card-Jitsu cards
- Main articles: List of Regular Card-Jitsu Cards (series 1-4), List of Regular Card-Jitsu Cards (series 5-8)
- Main article: List of Card-Jitsu Power Cards
Power Cards are special types of cards that have special effects when played or scored. These can vary from removing scored cards from your opponent, or increasing the value of your own cards. Power Cards also have animations when played, most being unique, although a few Power Cards share animations with others. As described by Aunt Arctic in issue 163 of the Club Penguin Times, "They have the ability to completely alter the world around you, and summon powerful objects to help you win." Power Cards are surrounded by a glow in-game, or have holographic borders in real life.