Materials are abundant in Age of Calamity and serve multiple purposes. They are dropped by defeated enemies, found in chests, or gathered from environmental objects. Materials are primarily used for completing requests, which unlock new services, character upgrades, and expand shops. They are also essential for cooking meals at the Mess Hall.
Keep a healthy stock of common materials like Bokoblin Horns, Lizalfos Talons, and various fruits and vegetables. Some rare materials are only dropped by specific powerful enemies or found in later missions. Always check the requirements for requests before selling off large quantities of materials. The 'Material Merchant' service, once unlocked, allows you to purchase missing materials, though often at a higher price.