In Kuutei Senki, every entity related to gameplay are represented by cards. There are 5 types of cards,
- Crew cards, representing the playable characters in this game.
- Battle cards, representing equipment to be used during battle, which are consumable (i.e. removed after being used). They're mainly weapons, buff items during battle, and some healing items.
- Event cards, which are "items" used for various purposes outside of battle, such as laying traps, manipulating your or your opponents' roulette values, quickly changing altitudes, warping, attacking enemies, healing in terms of percentage, dropping traps, etc. One "event" card can be used per turn (except E001, which you can use as many as you want per turn) before hitting the roulette/changing altitude.
- Monster cards, they're just collectibles that are unlocked upon facing the respective monsters, serving as bestiary.
- Important cards, most of which are event items acquired by progressing through the storyline, and apart from proof that you've accomplished things in the game, they're not of much use. However, the basic battle cards also belong to this category. Basic battle cards are reusable "basic attack" weapons, which are same as battle cards but are not consumed, and all crew can use them all the time, as many times as they want, even in the same turn. They're usually used as last resort weapons when you've run out of consumable battle cards or don't want to waste valuable battle cards on inferior enemies.