Gem (XC3)

Gems are items in Xenoblade Chronicles 3 that can be equipped to characters to provide certain advantages in battle, such as raising the user's stats.

Gems come in four different categories: Defender, Attacker, Healer, and Specialty. These categories have no mechanical effect, merely denoting the gem's color and which role it is most recommended for. Each gem comes in ten different ranks.

Crafting
Gems are craftable at most Rest Spots that are not canteens. Gems are made by combining various materials together. In addition to various other requirements, each gem requires at least one gemstone to act as its base, and all levels above the first require s as well.

If the player wishes, they can pay Gold s to receive a gem instead of crafting it. The resulting gem is the same.

Crafting a gem is instant, with no additional mechanics beyond providing the necessary materials. After crafting gems and closing the interface, the player is shown a cutscene of Riku and a randomly-chosen party member crafting the gem, with dialogue between that party member and the currently-controlled character.

Usage
Gems can be equipped to characters via the Characters menu. At first, characters can only equip one gem, but extra slots are unlocked as they level up - the second slot unlocks at level 20, while the third unlocks at level 40.

While they are obtained as inventory items, gems behave more like unlockables. Once a gem is obtained, the player is not allowed to make a second copy of that gem of equal type and rank, nor a gem of the same type but lower rank. In addition, crafting a gem allows all characters to equip it at once, though each character can only equip it in one slot at a time.

Heroes are automatically equipped with gems that cannot be changed by the player. Their gems increase in rank as they level up, and they can equip gems the player has not crafted yet.