Engram

Engrams are crystals; that are encoded with the patterns of armor, weaponry and other as-yet-undisclosed items. There are five known types of Engrams: Encoded, Encrypted, Decoherent, Legendary, and Exotic.

Encoded Engrams are sold by the Cryptarch, and are coded with the patterns of known items, such as a particular section of armor or class of weaponry. Once purchased by the Player, the Engram is converted into a random example of that item by the Cryptarch. While decoding an Engram will generate a random item, it's still possible to know the type of item that will be discovered. Each Engram will indicate whether the item is armor, a primary weapon, a special weapon, or a heavy weapon. The quality of the item is also identified, as Engrams use the same color coding as weapons and armor: White for basic, green for uncommon, blue for rare, purple for legendary, gold for exotic.

Encrypted Engrams are defined in-game as having "unusual properties". These must also be taken to the Tower where the Cryptarch will convert them if (in certain cases) only after he has attained the necessary Rank. The Cryptarch is also known to have these rarer Engrams for sale from time to time, which are more common if his skill is higher.

Engrams are also found as loot, and appear as colored crystals on the ground (white for encoded, green for encrypted, blue for decoherent, purple for legendary, gold for exotic). Enemies may drop them randomly, or they may be picked up from boss encounters or inside chests. Any engrams that the player hasn't picked up may show up in the Postmaster's office.

Decoding Engrams
Engrams have a chance of being decoded into an item that is higher, lower, or the same quality as the engram itself. Below is user-tested distribution for decoding probabilities.

Please note, the provided statistics are now outdated and require updating, due to the recent patch. Items will now only decode into the correct item catagory or higher value. Rare will now decode into rare, or legendary while legendary will only decode into legendary or exotic. This is the same for materials with the new classed ascendant materials being re-classed as legendary rather than rare.

Engram Types
The table below contains information on engrams purchased directly from the Cryptarch.

Legendary Engrams can be acquired via the Postmaster for each new reputation level if the player has a high enough rank with the Cryptarch by buying his stuff or by loot drop which are extremely rare.

Exotic engrams can be purchased from Xûr, Agent of the Nine for 23 Mote of Light.