Item or Monster rarity can be Normal (grey), Magic (blue), Rare (yellow) or Unique (brown). As a general rule, monsters increase in difficulty depending on their Rarity.

Magic and Rare Monsters have Modifiers which will augment them in many ways, making them more rewarding, but also more powerful and deadly. Magic Monsters will normally have a single Monster Modifier, whereas Rare Monsters have up to 4 by default.

Each Monster Modifier grants at least 100% increased Rarity of Items Dropped, and can grant the Monster additional abilities or permanant buffs.

Monster Modifier Chance increases the potential number of Rare Monster Modifiers with each modifier above 4 requiring twice as much Modifier Chance. Monster Modifier Chance above the maximum number of modifiers increases the chance Rare monsters will have maximum modifiers.

Other mechanics such as Azmeri Spirits, Essences and Delirium can add additional Monster Modifiers to monsters of any rarity.

A skill created by Ailith that creates a zone which upgrades the Rarity of Breach Monsters which enter it.

Monsters can only have their Rarity upgraded once, and can not be upgraded beyond Rare.