Unique Weapons are category of Weapons in Biomutant. Unique Weapons features improved Stats and usually deals elemental damage. Though you can modify most of them, if you switch a piece of the Weapon, this will change its name to a new one as it will become into a new and different Weapon. Unique Weapons are considered the Top Tier Weapons in Biomutant, and they can usually be obtained after completing certain Quests.
Each Weapon and Weapon Add-On in Biomutant have 3 qualifiers that define them: Rarity, Quality, and Material. Rarity is defined by the sum of the quality of the equipment and the add-ons you assigned to them. Therefore, as the quality and materials of any piece of equipment increases, its rarity will also be improved. There are 6 rarity levels:
Common ♦ Uncommon ♦ Rare ♦ Legendary ♦ Relic ♦ Ultimate
All Unique Weapons in Biomutant
Unique Ranged Weapons
Unique Melee Weapons