The game is viewed from a top-down perspective during exploration. Sora travels through rooms, fights Heartless in real time, opens treasure rooms, and uses map cards after battles to determine the layout and properties of new areas.

Combat depends on numbered attack, magic, summon, item, and enemy cards. Cards can be stocked into combinations, but higher values can break lower cards. Players gain experience, improve attributes, and expand their deck while progressing through Disney-themed worlds and the story of Castle Oblivion.

A separate Reverse/Rebirth campaign follows Riku with a more restricted card system and different progression rules.

Build separate decks for different purposes instead of relying on one general deck. Keep a mixture of high-value attack cards, reliable low-value cards, healing, and cards that can counter enemy attacks.

Use map cards carefully. Rooms with stronger rewards or special effects can help with deck development, while unwanted effects can make difficult fights harder. Stocking cards improves efficiency, but avoid spending every card at once if an enemy can break the whole sequence.

Leveling HP, CP, and card-related abilities according to your play style is important. Riku’s campaign rewards careful use of his fixed deck and attack patterns rather than the deck customization available to Sora.