These cards belong in the Main Deck, and share the same card backing as other cards in the deck. Like other trading card games, Items exist to help buff other cards. The rulebook suggests a 50 card deck should have around 5 Item cards. 19 Item cards were printed for the Legend of Mana Card Duel collectible card game.
Items are Equipped to Character cards, and remain in play until the equipped Character is trashed. Characters can typically use one Item, but some cannot or may be limited to only using specific Items. These limitations or abilities are described in the Character’s Equipment Remarks. When an Item card is equipped to a Character that already has an Item equipped, the original Item is trashed and the new Item takes its place.
Weapons enable Characters to use Special Techniques. The cost for these effects must be paid during battle. Only one Special Technique may be used per battle, but they may be activated as many times per turn as a player can afford. Weapons typically confer STR or DEF bonuses to Characters, but may have other interesting effects.
Magical Instruments, on the other hand, have no Mana costs associated with activating their spells. Instead, their effects activate depending on how many Lands of the matching element you have in play and not invaded by your opponent’s Monsters. Magical Instruments only confer STR to Characters, and offer additional STR against Monsters of specific elements.