Socket

A socket is a special slot on an item into which gems can be inserted to provide bonuses similar to those gained from enchanting.

There is currently no way to remove a gem once it has been placed into a socket. You can place another gem in the same socket, but doing so will destroy the existing gem (much like overwriting enchants).

Pocket-Sized Computation Device from Mechagon is a trinket that has sockets for specific punch card items.

Placing gems in sockets
Gems can be added to sockets in the "Item Socketing" window, which can be opened by holding shift and right-clicking on a socketed item. The gems are then dragged into the slots, and the "Socket Gems" button is pressed to apply the gems.

Socket types
Sockets are separated into the following types:


 * Prismatic Sockets - UI-EmptySocket-Prismatic.png
 * Cogwheel Sockets - UI-EmptySocket-Cogwheel.png
 * Meta Sockets - UI-EmptySocket-Meta.png
 * Sha-Touched Sockets - UI-EmptySocket-Hydraulic.png
 * Domination Sockets - UI-EmptySocket-Domination.png

Gems may be placed by anyone into a socketed item via a drag-and-drop interface, invoked by shift-right-clicking the weapon or piece of armor you want socketed.

Prismatic sockets
Prismatic (or uncolored) sockets are the default socket found in any item with gem sockets. They can also be added to an item by blacksmithing skills (or items created with blacksmithing such as the Eternal Belt Buckle). Any gem (except meta gems) may be placed in them.

Items that have a Sha-Touched socket can have one prismatic socket added to them by using Eye of the Black Prince.

Cogwheel sockets
Cogwheel sockets are engineering-only sockets first introduced in World of Warcraft: Cataclysm. Any class is capable of adding cogwheels to these sockets as long as they have the engineering skill to do so. Currently, the only known items that have cogwheels are the epic helms crafted by engineers with 75 skill points in Cataclysm or Pandaria engineering.

The cogwheels themselves are purchased in Twilight Highlands, Stormwind, or Ironforge using other engineering crafted items as currency.

Meta sockets
Meta sockets are only found on high-level head gear from The Burning Crusade to Mists of Pandaria (currently only in particular varieties of head items). Meta sockets only accept meta gems, and meta gems may only be placed in meta sockets.

Prior to patch 7.0.3, a meta gem introduced before Mists of Pandaria would be inactive unless certain requirements were not met, such as equipped items being socketed with a certain number and color of other gems.

Sha-Touched sockets
Sha-Touched sockets are only found on weapons from Grand Empress Shek'zeer in Heart of Fear and Tsulong, Lei Shi and Sha of Fear in Terrace of Endless Spring. Sha-Touched sockets only accept Sha-Touched gems.

Domination sockets
Domination sockets were introduced in patch 9.1 from items dropped in the Sanctum of Domination. They can only be filled with Shards of Domination, which also drop from the raid.

Colored sockets
Prior to patch 7.0.3, the majority of sockets found on equipment were Red,  Yellow, and  Blue sockets. While any gem could be put in any of these socket types, the item socket bonus would only be activated if all of the sockets were filled with the matching gem color.

With the exception of meta gems, all gems matched one or more of these colors.
 * Primary-color gems — red, yellow, and blue — would only match into the specific sockets for their color.
 * Secondary-color gems — green, orange, and purple — would match into either of the two slots that correspond to their color. (For example, an orange gem would match a red or yellow slot for the bonus.)
 * Prismatic gems would match any of the three socket colors.

History
Sockets were introduced in The Burning Crusade and modeled after a similar concept using gems in Diablo II, though the method of replacing them is different. The rune word system in the Diablo II expansion Lord of Destruction, which added additional bonuses if a particular set of runes was inserted in a particular order, has not been replicated in WoW — special combinations of gems do not confer any bonuses except the item's pre-defined socket bonus, unless using a meta gem.

As of patch 3.0.2, Blacksmiths with skill level 400+ are able to permanently place an additional socket on their bracer and glove, making the socketed item soulbound. Blacksmiths were originally given the ability to socket one-handed weapons, but this appears to not have been implemented in a patch release (although it is referenced in the game files).

A blacksmith with skill level 425+ can make an Eternal Belt Buckle, which can be used by anyone (even sold via the Auction House) to add a prismatic socket to a belt, making the belt soulbound.

Starting with Warlords of Draenor, no items have a socket by default. Instead, every item that drops from a dungeon has a small chance to have a prismatic socket.