Quality is a property of cosmetic items. It is represented in-game by the item's prefix and color.
Quality is a purely cosmetic property, and has no effect on gameplay. Items can have both a Quality and a Rarity value.
Inscribed items have a counter that tracks a specific in-game statistic. A regular item can be changed to Inscribed quality by placing an Inscribed Gem into a socket. Inscribed items can also be unboxed from Treasure Chests. These items come with an Inscribed gem.
Tracked counters are viewable by other players. Other than this, Inscribed items are no different from regular items.
Unusual is a special prefix for couriers that have a special particle effect. To date, no official items are titled "unusual" even if they possess their own particle effect. Unusual couriers are found in Treasure Chests at an approximately 1-2% chance.
Elder is a special prefix for limited items obtained under certain circumstances. To date, there are six Elder items.
Heroic is a special prefix for commemorative items dropped for spectators during a live tournament game.
Genuine is a special prefix for limited items obtained under promotional circumstances. They are obtained as bonus items by purchasing certain merchandise.
Self-Made is a special prefix for items that were submitted to the Steam Workshop which were accepted and added to the game. They are given out to the creator(s) of the item by Valve. Self-Made items cannot be chiseled, socketed, or hammered.
Items awarded to professional players that win the Compendium team/player vote.
Autographed items are inscribed with an Autograph Rune, bearing the digital signature of a notable member of the Dota 2 community.
Ascendant items are inscribed with an Ascendant Gem. Ascendant items track the number of Dota 2 Beta invites sent, or victories during the beta period.
Part of the Frostivus/Wraith Night event for 2013. Items unlocked through redeeming fragments have this quality.
Part of the Frostivus/Wraith Night event for 2013. Items created using the recipe Recipe: Wraith King's Relic will have this quality. These items comes socketed with a Foulfell Shard. The Corrupted quality can be transferred by transferring the gem.
Items unboxed from New Bloom Festival 2014 gifts.
 See also