Gems

Active skill gems and support skill gems are usually referred to as skill gems and support gem in in-game item mod and passive skills. In item filter and gaming community they are still refer as Skill gem.

Gems must be equipped in item sockets before their use. Active skill gems grant an active skill for the player to use and are further augmented by linked support skill gems. There are currently 276 different active skill gems and 177 support skill gems in the game, for a total of 453.

Skill gems are not to be confused with passive skills, which provide constant stats and are mainly earned through character levelling. To avoid confusion, some players simply refer to both types of these items as "gems". The "Skill gem" in in-game modifier also refer to Active skill gems exclusively.

Obtaining gems

There are several methods of obtaining skills and support gems:

• Earned through a quest reward (see List of skill gems rewarded from quests).
• Purchased from town vendors once a certain quest is complete (see List of skill gems rewarded from quests).
  • Vendors in Acts 1-4 towns sell leveled skill gems. The available gems are based on the character's class and quest progression.
  • Siosa in Act 3 sells all unleveled skill gems that can be received as quest rewards for quests you've completed, across all classes.
  • Lilly Roth in Act 6, 10 and Karui Shores sells all unleveled skill gems after completing the Act 6 quest Fallen from Grace quest icon.png Fallen from Grace.
• Vendor recipes (see VendorRecipes).
• Random drop from monsters, chests and strongboxes
• Vaal skill gems are obtained from Vaal Vessels in corrupted areas or by Corrupting a regular skill gem.
• As a reward for turning certain sets of DivinationCards.
• BestiaryRecipe

Gem levels

Experience

• Socketed gems gain 10% of the experience your character earns, calculated before any level penalties.
• The number of gems you have equipped has no effect on the rate of experience gain.
• Gems do not lose experience when you die.
• Items with +experience% gain do affect gems.
• Gems socketed in inactive weapon slots do gain experience.
• Gems may be traded like normal items and they will retain their experience.

Once a gem has enough experience to level up, it will stop gaining experience and a level–up icon will appear on the right of the screen and in the inventory menu. Left–clicking it will level up the gem, right–clicking the icon will hide it on the side of the screen, but it will still be accessible in the inventory menu. Not levelling up a gem is useful in some situations.

As gems level up, the abilities they grant get better, but the requirements to equip them also increase, as well as the mana cost for active skills. Each gem level, the exile must have both the attribute corresponding to gem colour and a character level high enough to meet its increased requirements. If a gem gains enough experience to level up, but the exile currently does not meet the requirements, the level–up icon will appear greyed out and not be useable until the requirements are met. For specifics, see the lists of active skills and support gems below.

Items that alter experience gain

• Mutated Growth
• Perandus Signet
• Dialla's Malefaction
• The Supreme Truth
• Chitus' Apex
• Voidhome

Exceeding the level cap

Each gem has a cap beyond which it can not gain any further experience and can not advance any more levels through experience; for most gems this cap is at 20. There are, however, ways to increase the level of a gem beyond 20.

They can be placed in items with modifiers such as the Paragon's - +1 to Level of Socketed Gems (Prefix) or certain Corruptions, or certain unique items such as Frostferno. They can also be linked with the support gems Empower Support, Awakened Added Fire Damage Support, Awakened Added Cold Damage Support, Awakened Added Lightning Damage Support, Awakened Added Chaos Damage Support, Awakened Blasphemy Support, and Awakened Generosity Support, and corrupting a gem can raise its level permanently (ignores level cap, suggest corrupting when the gem is at level 20).

Attribute and level requirements no longer increase when using any of those methods with the exception of corrupting the gem itself.

For example, by combining these three methods, the level of a skill gem can get as high as level 32. One way to do this is to have a Frostferno with two additional instances of the +2 to Level of Socketed Fire Gems and +2 to Level of Socketed Cold Gems modifiers via corruption, then socket a corrupted level 21 Elemental Hit gem in to the Frostferno item. This is now a level 29 Elemental Hit. Now support it with a corrupted level 4 Empower Support, increasing the Elemental Hit's level by 3 to bring it to level 32.

Quality

A Gemcutter's Prism can be used to upgrade a gem's quality. Adding quality to a gem will add an additional effect to the skill. The exact modifications quality gives to the gem are displayed in the detailed view (hover over the item and hold Alt).

The effect of quality scales with the base quality effect, however, only whole numbers will be granted (and thus the effect will always be rounded down); for example 3% quality on a gem with 0.5% effect will only grant 1% effect and not 1.5% effect. Effects that have some degree of fractions naturally are rounded to their natural bases (i.e. seconds will be rounded to milliseconds, etc.).

Gems with alternate quality effects can be found in Grand Heists. They are prefaced as "Anomalous", "Divergent", or "Phantasmal" instead of "Superior".

Corruption

Like most items, gems can be Corrupted using a Vaal Orb. Corruption on gems can potentially lift the level or quality percentage of a gem above the maximum of 20. Corruption can also convert a gem into its Vaal skill equivalent, if one exists. It's suggested that you apply Corruption to a Skill Gem when the Skill gem is at level 20, 20% quality or both in order for corruption to potentially exceed the cap.

After the release of Incursion league, it became possible to achieve "double-corruption" of a gem by using the Lapidary Lens device in The Temple of Atzoatl. The device corrupts a skill or a support gem twice, which makes possible to apply two different effects of corruption at once. This allows to receive a level 21 gem with 23% quality.