Identify is a mechanic in Diablo series.
Each item of quality higher than Normal (in Diablo I and Diablo II) or higher than Rare (Diablo III), when dropped, will be Unidentified. This means that the item's affixes and properties are unknown, and will be hidden and have no effect until the item is Identified.
The item's properties are determined at the moment it is dropped, not when Identified. They will just be hidden and inactive until unlocked via Identify.
There are multiple means, depending on the game, to Identify an item, but the result is same: the item gains a new name (other than its basic type with appropriate color), can be used, and the affixes are unlocked and disclosed.
The system of unidentified items serves multiple purposes, mostly giving players incentive to pick items up and see their properties, giving excitement of discovering what the real use of an item is.
Any object imbued with magic exhibits an aura that is easily noticed. To determine the exact nature of this enchantment, however, requires intense study and an extensive knowledge of arcane materials and symbols. While none have mastered the ability to memorize a spell of this magnitude, the Vizjerei have developed a means for the untrained to discover the secrets of an ensorcelled object by using a rare crystal that is extremely sensitive to magical auras. This sensitivity makes it very fragile, however and the crystal will shatter if it is brought too close to an enchanted item. The very act of Identifying such an object also destroys the crystal. Scrolls and staves have been crafted that can be used to Identify magical auras. By using special inks and dyes that contain tiny grains of these crystals, the stability of the crystal is maintained until it is used to examine the enchanted object.
Reveals the hidden properties of an item.
Damage Type: Magic
Identify is both a spell and a skill in Diablo I. As a spell, it can be used by any class, but cannot be learned from books. As a skill, it is only utilized by Bards, and is arguably the most useful of all class skills in game.
Identify, when invoked, instantly reveals the properties of an unidentified item so that it can be used. It is not available as an spell, but can be found on scrolls and staves. Scroll of Identify was even carried over to Diablo II.
Identify can be cast on any item in the player's inventory. Once the scroll is invoked, it cannot be canceled, and if cast on an item already identified, or not suitable for identification, it is lost.
It may be a good idea to save the game before identifying items, for with some bad luck, the selling price of loot may be below 100 gold, leaving player at no profit for selling the identified item.
With the knowledge of the ages stored in their minds from hearing the endless tales of other Seekers, young bards learn to immediately identify any item that they find, no matter how obscure or foreign.
Due to the complete overhauling of the Skill system in Diablo II, Identify was robbed of its Spell status and transformed into a mere scroll that may drop from monsters or be bought from magical vendors.
In Diablo II, the act of Identifying is limited to the act of using a Scroll of Identify on an unidentified item, Tomes of Identify are used in a similar manner. This is performed by right-clicking the Scroll and clicking of an item to identify it. Unlike the first game scrolls, scrolls in the second game are not wasted if misclicked or canceled.
The result is that the hidden attributes will be shown. Also, unlike Diablo I, the second game nearly always makes this a positive change, as there are no negative attributes in Diablo II, except in some Unique Items. Also, unidentified items merely sell for the price of the standard equipment version, in addition to being useless as they cannot be equipped.
Deckard Cain can still identify items while in town. This time, he performs it for free if rescued during the Search for Cain. If not rescued by player character (done by simply clicking his cage), he will be rescued by the Sisterhood of the Sightless Eye, and will charge 100 gold for each item. In either case, he has an option to identify all items at once.
He will show up in multiplayer games and have the same function for players who have not done the quest, for 100 gold per item. Since scrolls only cost 80 gold, it is slightly more expensive if you haven't done the quest, but it saves you time.
The power of identification returns in Diablo III, though somewhat changed. Scrolls are no longer necessary for the Nephalem, as they have an identification power of their own, though this is outmatched by Deckard Cain, as well as his book.
Originally, the scrolls of identification were implemented, but over the course of development and releasing of patches, the identification process was becoming less strict. At first, the scrolls were removed and replaced with right-clicking and channeling the spell for 3 seconds. Magic quality items no longer need to be identified. Prior to the pre-expansion patch, Rare items required identification, but since then, no longer require such. As result, only Legendary and Set items require identification.
To identify many items at once, players can use the Book of Cain or (in the first half of Act I, they can also ask Cain for help).
This action, once begun, requires concentration. The hero cannot do anything, even performing an instantaneous action, and will immediately lose progress if attacked, no matter how damaging the successful blow. As such, it is unwise to identify items in the middle of battle.
Identifying a Legendary/Set item, or using Deckard Cain's services, book or not, requires 4 seconds of concentration.