Backpacks currently come in eighteen designs. 14 of them can be purchased from NPC traders, the other can be acquired by completing certain quests or looted from monsters.
While runes are now stackable, some players still advertise "BP of SD" meaning 60 SD runes for example. Sometimes people use colored Backpacks to organize runes, like using a purple backpack to store HMMs, blue for UHs, red for GFBs and golden for Magic Wall
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