Upgrade Cores

Each item has a material grade and must be upgraded with a matching Core grade. Upgrade Cores do not destroy the item on failure — the upgrade level either stays the same or drops by 0, 1, or 2 points, depending on the core type. The four grades are: Low (Shadowsteel/Aramid and lower), Medium (Bluestin through Shadowtitanium), High (Osmium through SIGMetal), and Highest (Forcium through Drei Frame and beyond).

Force Cores are a separate type used for the Option Granting System. They must match the grade of the item being modified. Force Core (Highest) covers Forcium through Lycanus and Drei Frame items and drops from advanced dungeons including Mutant Forest, Porta Inferno, Forgotten Temple, Forbidden Island, Illusion Castle, all DX Dungeons, and Chaos Arena levels 3–6.

Slot Extenders add one extra equipment slot to armor pieces and can only be applied once per item. After use the item becomes account-bound. Slot Extender (High) works on Redosmium-grade items and below; Slot Extender (Highest) works on Mithril, Lycanus, and Drei Frame items. Both types also improve the abilities of Force Cores placed in the item's slots when the extension succeeds.

The Core Alchemist is an NPC found in every main town. They sell Crystals, Orbs, potions, rings, and amulets, and are the primary vendor for upgrade-related consumables. Named Core Alchemists include Keller in Bloody Ice, Nodaka in Green Despair, Sullivan in Desert Scream, Yerte in Port Lux, and Soyoung in Fort Ruina.