The following support gems are recommendations by GGG as listed in-game, and do not necessarily reflect optimal combinations or the views of the wiki.
Gem tier
Support gems
I
Multishot IMultishot ISupport, Projectile Category: Additional Projectiles Tier: 1Support Requirements: +5 DexSupports Projectile skills, making them fire extra Projectiles. Also lowers Attack and Cast speed of supported skills, as well as lessening their damage.Supported Skills deal 35% less Damage Supported Skills fire 2 additional Projectiles Supported Skills have 20% less Skill SpeedPlace into a Skill's Support Gem socket in the Skills Panel to apply its effects to that Skill. You cannot have multiple Support Gems of the same Category socketed within one Skill.
Projectile Acceleration IProjectile Acceleration ISupport, Projectile Category: Projectile Speed Tier: 1 Cost & Reservation Multiplier: 120%Support Requirements: +5 DexSupports Projectile skills, making those Projectiles travel faster.Supported Skills have 40% more Projectile SpeedPlace into a Skill's Support Gem socket in the Skills Panel to apply its effects to that Skill. You cannot have multiple Support Gems of the same Category socketed within one Skill.
Rapid Casting IRapid Casting ISupport, Spell Category: Rapid Casting Tier: 1Support Requirements: +5 IntSupports Spells, causing them to cast faster.Supported Skills have 15% increased Cast SpeedPlace into a Skill's Support Gem socket in the Skills Panel to apply its effects to that Skill. You cannot have multiple Support Gems of the same Category socketed within one Skill.
II
Cold PenetrationCold PenetrationSupport, Cold Category: Cold Penetration Tier: 2 Cost & Reservation Multiplier: 120%Support Requirements: +5 IntSupports any skill that Hits enemies, making those HitsPenetrate enemy Cold resistance.Supported Skills Penetrate 30% Cold ResistancePlace into a Skill's Support Gem socket in the Skills Panel to apply its effects to that Skill. You cannot have multiple Support Gems of the same Category socketed within one Skill.
Cold PenetrationCold PenetrationSupport, Cold Category: Cold Penetration Tier: 2 Cost & Reservation Multiplier: 120%Support Requirements: +5 IntSupports any skill that Hits enemies, making those HitsPenetrate enemy Cold resistance.Supported Skills Penetrate 30% Cold ResistancePlace into a Skill's Support Gem socket in the Skills Panel to apply its effects to that Skill. You cannot have multiple Support Gems of the same Category socketed within one Skill.
Considered CastingConsidered CastingSupport, Spell Category: Considered Casting Tier: 2 Cost & Reservation Multiplier: 115%Support Requirements: +5 IntSupports Spell Skills that Hit Enemies and you cast yourself, boosting Damage at the cost of Cast Speed.Supported Spell Skills have 15% less Cast Speed Supported Spells deal 35% more DamagePlace into a Skill's Support Gem socket in the Skills Panel to apply its effects to that Skill. You cannot have multiple Support Gems of the same Category socketed within one Skill.
III
DeliberationDeliberationSupport Category: Deliberation Tier: 3Support Requirements: +5 DexSupports skills that can be used while moving, causing you to move slower while using them, but granting more damage in exchange.Supported Skills deal 20% more Damage 30% more Movement Speed penalty while using Supported SkillsPlace into a Skill's Support Gem socket in the Skills Panel to apply its effects to that Skill. You cannot have multiple Support Gems of the same Category socketed within one Skill.
Elemental FocusElemental FocusSupport Category: Elemental Focus Tier: 3Support Requirements: +5 IntSupports any skill that Hits enemies, causing it to deal more Elemental Damage but be unable to inflict Elemental Ailments.Supported Skills deal 25% more Elemental Damage Supported Skills cannot inflict Elemental AilmentsPlace into a Skill's Support Gem socket in the Skills Panel to apply its effects to that Skill. You cannot have multiple Support Gems of the same Category socketed within one Skill.
Zenith IIZenith IISupport, Spell Category: Zenith Tier: 3 Cost & Reservation Multiplier: 120%Support Requirements: +5 IntSupports Spell Skills. Supported Skills deal more damage while you are above 90% of your Maximum Mana, and Recoup a portion of Skill costs as Mana. Does not modify Skills used by Minions.25% of Supported Skills costs are Recouped as Mana Supported Spells deal 30% more Damage while you are above 90% of your Maximum ManaPlace into a Skill's Support Gem socket in the Skills Panel to apply its effects to that Skill. You cannot have multiple Support Gems of the same Category socketed within one Skill.
IV
Projectile Acceleration IIProjectile Acceleration IISupport, Projectile Category: Projectile Speed Tier: 4 Cost & Reservation Multiplier: 120%Support Requirements: +5 DexSupports Projectile skills, making those Projectiles travel faster, and granting them a chance to Pierce Enemies.Projectiles from Supported Skills have 40% chance to Pierce an Enemy Supported Skills have 40% more Projectile SpeedPlace into a Skill's Support Gem socket in the Skills Panel to apply its effects to that Skill. You cannot have multiple Support Gems of the same Category socketed within one Skill.
Rapid Casting IIRapid Casting IISupport, Spell Category: Rapid Casting Tier: 4Support Requirements: +5 IntSupports Spells, causing them to cast faster.Supported Skills have 20% increased Cast SpeedPlace into a Skill's Support Gem socket in the Skills Panel to apply its effects to that Skill. You cannot have multiple Support Gems of the same Category socketed within one Skill.
V
Cold MasteryCold MasterySupport, Cold Category: Mastery Tier: 5Support Requirements: +5 IntSupports Cold skills, granting them an additional level. Does not support skills which do not have levels.+1 to Level of Supported Cold SkillsPlace into a Skill's Support Gem socket in the Skills Panel to apply its effects to that Skill. You cannot have multiple Support Gems of the same Category socketed within one Skill.
Projectile Acceleration IIIProjectile Acceleration IIISupport, Projectile Category: Projectile Speed Tier: 5 Cost & Reservation Multiplier: 120%Support Requirements: +5 DexSupports Projectile skills, making those Projectiles travel faster, and causing increases and reductions to Projectile speed to also apply to Damage.Increases and reductions to Projectile speed also apply to Projectile Damage with Supported Skills Supported Skills have 40% more Projectile SpeedPlace into a Skill's Support Gem socket in the Skills Panel to apply its effects to that Skill. You cannot have multiple Support Gems of the same Category socketed within one Skill.
Item acquisition
Frost Darts has restrictions on where or how it can drop.