Just like in Breath of the Wild, Korok Seeds are hidden throughout the battlefields of Age of Calamity. There are over 100 Korok Seeds to find. Each mission has a set number of seeds, often hidden in obscure locations, behind destructible objects, or requiring specific actions to reveal. Collecting Korok Seeds is essential for expanding your weapon inventory slots at the Korok Forest.
To find Korok Seeds, keep an eye out for suspicious objects, sparkling spots, or unique environmental puzzles. Some require you to destroy a specific object, others to interact with a pinwheel, or even to find a hidden Korok. The Korok Forest service, unlocked early in the game, allows you to trade your collected seeds for more weapon slots, which is vital for managing your growing arsenal.