The four main subtypes are ally, action, trap, and object:
- Ally cards are the only cards that have a specific amount of HP (health points) and AP (attack points), and are able to attack and defend. Most allies can only be played in the Main phase, although allies with the ability Ambush can be played during the Defense phase.
- Actions are cards that do a specific thing, such as deal direct damage or heal a player, and can be stopped with cards like Interfere. Usually, with a few exceptions such as Ant Invasion, actions do not directly interfere with the playing of allies.
- Traps are cards that are benched and are activated by a specific thing happening during the game. For example, Booby Trap is activated by the opponent playing a low-HP ally.
- Objects are cards that cannot be removed from the field after being played unless they are subject to an object-removal card such as Fresh Force. Objects have unique effects that are either global, local, or foreign: global affecting both you and your opponent, local affecting only you, and foreign affecting only your opponent.