Treasure and Rarity

Giving out uncommon and rare items can get players more interested in treasure. These rewards are especially compelling when the adventurers get the item by defeating or outsmarting an enemy who carries an item that fits their backstory or theme.

Uncommon and rare formulas make great treasure for a character who Crafts items. Note that if an uncommon or rare formula is broadly disseminated, it eventually becomes more common. This can be almost instantaneous if leaked on the infosphere, and it's usually impossible to contain information once it's been released online.