The quality of an item in the world of Terraria is determined by the color of its name. There are currently eleven tiers of item quality.
Note that all items which can be reforged can vary in quality by several tiers, depending on which prefix they get. As such, except where otherwise noted, the guidelines below only apply to the base quality of the items in question.
Tier -1: Gray
Tier -1 items are those that have labels such as "Shameful", "Weak", "Annoying", or "Broken" after being crafted or reforged and have a gray name. Generally only Tier 1 items can be reduced to this tier of quality but since 1.2.4, items obtained by fishing such as Tin Can are normally gray quality items. Higher tier items are incapable of reaching Tier -1, even if they have weakening prefixes.
Tier 0: White
Many items which are craftable early in the game are Tier 0. This Copper Helmet is an example of such an item. With the exceptions of Obsidian, Fireblossom, and Fireblossom Seeds, items of this tier are destroyed when in lava that is deep enough to cover approximately 25% of the item.
Tier 1: Blue
Tier 2: Green
Tier 3: Orange
Weapons and armor made of Hellstone are tier 3. Certain uncraftable weapons are tier 3, such as the Staff of Regrowth, Feral Claws and the Flower of Fire. These items are usually found later in pre-hardmode.
Tier 4: Red
Tier 5: Pink
Certain items at or slightly below the Hallowed tier are naturally Tier 5.
Tier 6: Purple
This quality is on late game items (Prior to 1.2) such as anything in the Hallowed Set, and some items with top-tier effects, such as Legendary, Mythical and Unreal. This can be achieved by reforging items or looting chests. This does not apply to all top-tier forged items. It is also the rarity of the Console exclusive end game items like Tizona or the Dragon Armor.
Tier 7: Lime
Tier 8: Yellow
This quality tier is held by 1.2 endgame items such as the Keybrand, the True Excalibur and the Terra Blade.
A very few pre-hardmode items like the Diamond Ring (vanity item) and the Bundle of Balloons are Tier 8. Some unobtainable items such as the S.D.M.G. or Steampunk Wings are also Tier 8.
Tier 9: Turquoise
A quality only achievable through 2 ways:
- Reforge a Tier 8 item with a good prefix (eg. Legendary Keybrand, Unreal Pulse Bow, Mythical Shadowbeam Staff), or obtain an item with any said tier with good prefixes when dropped.
- Get one of the items which are impossible to get through normal gameplay (eg. Red's Wings or Red Potion).
Note that this is the final quality tier. Even via reforging items like Red's Wings, this quality tier cannot be topped as of 1.2.
- If an item has a negative prefix, i.e Broken, Annoying, etc., the item's rarity may be lowered by 1-2 tiers.
- The same goes for helpful prefixes, i.e Unreal, Nasty, etc., the item's rarity may be improved by 1-3 tiers.
- If an item has a -1 Tier, it will not get destroyed by lava.
- Rarely, on the Xbox 360 or the Playstation 3, items with negative prefixes may be interpreted by the game as good, raising the tier. The reverse may apply for positive prefixes.