Card Break

Card breaks only apply to the card-based battle system of Kingdom Hearts: Chain of Memories and Kingdom Hearts Re:Chain of Memories. All cards have a certain value, which may be nullified, or "broken", by a card of equal or greater value. Cards may also be broken by another card with a value of zero. Most often this is used to break sleights (three cards stocked together to produce certain combat moves or a higher card value). However, neither combatant will attack if both play with equal numbered cards, which results in a very quick temporal stun for the one who played the card first. In Kingdom Hearts Re:Chain of Memories, successfully breaking the opponent's cards right after it is used (a "Rapid Break") will boost Riku's attack strength.

The card break system is applied to an extent in the opening of new rooms in Kingdom Hearts: Chain of Memories: the player will need a certain quantity or total value of Map Cards to "break" open doors. If Sora or Riku presents an amount or value of Map Cards equal to that which is requested, he can access the next chamber.

DP
Card breaks are essential on the archivement of Dark Points. Riku gets a certain amount of DP every time he breaks a card, the amount of DP he gets is the value of his card minus the value of the enemy card. When he performs a Rapid Break, he gets DP the same way as a normal break, plus 5 bonus points. The best way to get lots of DP fast, is to use sleights.

Sleight Tricks
In Sora's story, premium cards are very useful in sleights. Premium cards will be lost after the first use in battle. If premium cards are used as the first card, no extra cards will be lost.