Gear - Item Level - Help
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As you progress through the story, the level of maps will increase.
In higher-level maps, you'll find gear with higher item levels.
Gear with a higher item level is more likely to receive rare affixes via crafting.

Gear - Affix Level - Help
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Each affix on gear is assigned a level that can be inspected in the gear details. Affix levels are related to the item level. For every 10 levels, a higher grade of affixes is unlocked.
The higher the affix level, the stronger the effects.

Gear - Energy - Help
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Energy is one of the base gear stats. It only appears on items with a sufficient item level.
Weapons and Chest Armor usually provide more Energy than other items while trinkets don't have Energy.

Gear - Legendary Gear Rarity - Help
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Legendary gear is categorized into various rarities: Common Legendary gear, Fine Legendary gear, Precious Legendary gear, Rare Legendary gear, and Ultimate Legendary gear. These rarities will be visually indicated by drop frames with distinct colors.