Contagion

ContagionBarrageable, Spell, AoE, Chaos, Duration
Tier: 1
Level: (1-20)
Cost: (9-95) Mana
Cast Time: 1.00 secAfflict a single enemy with a Debuff that deals Chaos damage over time. If the enemy dies while affected by Contagion, it and all other Chaos damage over time Debuffs spread to nearby enemies and refresh their durations. Reanimating or detonating a corpse affected by Contagion will cause the Minion or explosion to
spread Contagion on hit.Deals (1.9-86.7) Base Chaos Damage per second
Modifiers to Spell Damage apply to Debuff's Damage over Time
Debuff deals 100% more Damage for each
time it has spread, up to 300%
Spread radius is 1.7 metres
Debuff duration is 5 seconds

Additional Effects From 1-20% Quality:
+(5-100)% to maximum Debuff Damage bonus from spreadingSkills can be managed in the Skills Panel.

Acquisition
Drop restricted
It can be obtained by engraving an Uncut Skill Gem.Metadata
Item class: Skill Gem
Metadata ID: Metadata/Items/Gems/SkillGemContagion

Contagion is an AoE Chaos Duration Spell Skill that applies a spreading Chaos Damage over time Debuff. Enemies killed while having the debuff will spread Contagion and any other Chaos damage over time debuffs on them to nearby enemies.

Skill functions and interactions

Enemies that are affected by Essence DrainEssence DrainBarrageable, Spell, Projectile, Chaos, Duration
Tier: 3
Level: (1-20)
Cast Time: 0.80 sec
Critical Strike Chance: 7.00%Fire a Projectile that applies a powerful Chaos damage over time debuff to enemies it hits.Projectile
Deals (5-129) to (9-240) Chaos Damage

Damage over Time
Modifiers to Spell Damage apply to Debuff's Damage over Time
Debuff duration is 4 seconds
Deals (9.2–409.4) Base Chaos Damage per second

Additional Effects From 1-20% Quality:
+(0–1) second to Debuff durationSkills can be managed in the Skills Panel.'s damage over time debuff appear to be prioritized targets when casting Contagion.

Contagion also spreads curses similarly to the damage over time debuff regardless of whether or not Decaying HexDecaying HexSupport, Chaos, Curse
Category: Decaying Hex
Tier: 3
Cost & Reservation Multiplier: 130%Support Requirements: +5 IntSupports Curse skills. Cursed enemies' bodies decay, taking Chaos damage over time.Supported Skills inflict Decay, dealing 100% of Intelligence as Chaos damage per second for 8 secondsPlace 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. is linked to the curse. This is particularly synergistic with DespairDespairSpell, AoE, Chaos, Duration, Curse
Tier: 9
Level: (1-20)
Cost: (41-178) Mana
Cast Time: 0.70 secCurse all targets in an area after a short delay, lowering their Chaos Resistance.Curse applies after 1.5 seconds delay
Curse inflicts -(35-49)% to Chaos Resistance
Curse radius is (1.5-3.1) metres
Curse duration is (6-7.4) seconds
Curse does not apply to enemies above level (20-0)

Additional Effects From 1-20% Quality:
(0.5-10)% increased Curse MagnitudesSkills can be managed in the Skills Panel. or Temporal ChainsTemporal ChainsSpell, AoE, Duration, Curse
Tier: 7
Level: (1-20)
Cost: (41-178) Mana
Cast Time: 0.70 secCurse all enemies in an area, Slowing them and making other effects on them expire more slowly.Curse applies after 1.5 seconds delay
Curse radius is (1.5-3.1) metres
Curse Slows targets by (40-59)%
Curse duration is (6-7.4) seconds
Curse makes other effects on targets expire 25% slower
Curse does not apply to enemies above level (20-0)

Additional Effects From 1-20% Quality:
(0.5-10)% increased Curse MagnitudesSkills can be managed in the Skills Panel..

Gem level progression

Level			Mana Cost	Chaos Damage
1	0	0	8	1.9
2	3	9	9	2.8
3	6	14	11	4.1
4	10	21	13	5.5
5	14	28	15	7.2
6	18	35	17	9.1
7	22	41	19	11.2
8	26	48	22	13.7
9	31	57	25	16.5
10	36	65	28	19.7
11	41	74	32	23.4
12	46	82	36	27.6
13	52	92	40	32.5
14	58	103	45	38
15	64	113	50	44.4
16	66	116	55	51.7
17	72	126	61	60.1
18	78	137	68	69.8
19	84	147	75	81
20	90	157	83	93.9

Recommended support gems

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	Magnified Area IMagnified Area ISupport, AoE Category: Increased Area of Effect Tier: 1 Cost & Reservation Multiplier: 130%Support Requirements: +5 IntSupports any skill with an area of effect, making it larger.Supported Skills have 35% increased Area of EffectPlace 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.	Minion Pact IMinion Pact ISupport, Minion Category: Minion Pact Tier: 1Support Requirements: +5 IntSupports damaging skills you use yourself, draining the life from one of your Minions on use in order to boost the skill's damage. Only takes effect if you have a Minion with enough life to drain the full amount.Supported Skills remove 100% of your maximum Life from a nearby Minion on use to deal 30% 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.	Profanity IProfanity ISupport, Chaos Category: Profanity Tier: 1Support Requirements: +5 IntSupports Skills you use yourself. Supported Skills consume a Corpse on use, dealing more Chaos Damage if they do. Cannot support Triggered Skills or Reservation Skills.Supported Skills consume a Corpse within 5 metres on use, if possible Supported Skills deal 30% more Chaos Damage if consuming a CorpsePlace 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	AcrimonyAcrimonySupport Category: Acrimony Tier: 2 Cost & Reservation Multiplier: 110%Support Requirements: +5 IntSupports Skills which can Damage Enemies. Enemies affected by Damage over time from Supported Skills which was not caused by a Damaging Ailment have reduced Life regeneration rate. Only the strongest instance of this Debuff will apply. Does not Support Skills used by Minions.Enemies affected by non-Ailment Damage over time from Supported Skills have 50% reduced Life regeneration ratePlace 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.	Intense AgonyIntense AgonySupport, Spell, Duration Category: Intense Agony Tier: 2Support Requirements: +5 IntSupports Spells that deal non-Ailment damage over time, causing them to have a shorter duration but deal substantially more damage over time with Debuffs inflicted against enemies on full life.Damage over time with non-Ailment Debuffs inflicted on full-life enemies by Supported Skills deal 50% more damage Supported Skills have 25% less Skill Effect DurationPlace 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	Chaotic FreezeChaotic FreezeSupport, Spell, Chaos Category: Chaotic Freeze Tier: 3Support Requirements: +5 IntSupports Spells that deal non-Ailment Chaos damage over time. Enemies taking damage over time from Debuffs caused by supported skills will suffer Freeze build up from Chaos damage Hits from any source. Does not Support Skills used by Minions.Chaos damage Contributes to Freeze buildup for Hits against targets taking damage over time from 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.	Drain AilmentsDrain AilmentsSupport, Spell Category: Drain Ailments Tier: 3Support Requirements: +5 IntSupports Spells that deal non-Ailment damage over time, causing them to consume Ailments on enemies it applies damage over time Debuffs to in order to deal substantially more damage over time.Supported Skills Consume all Ailments of a random type on the target when inflicting damage over time Debuffs, causing the Debuff to deal 35% more damage if any Ailments were consumedPlace 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.	Prolonged Duration IIProlonged Duration IISupport, Duration Category: Prolonged Duration Tier: 3 Cost & Reservation Multiplier: 120%Support Requirements: +5 StrSupports any skill that has a duration, making that duration longer.Supported Skills have 35% more Skill Effect DurationPlace 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	DerangeDerangeSupport Category: Derange Tier: 4Support Requirements: +5 IntSupports Skills which you use yourself which can deal damage. Supported Skills gain an Energy Shield cost equal to your Intelligence, while also dealing more non-Ailment Damage over time based off of your Intelligence. Cannot support Channelling Skills.Supported Skills gain an Energy Shield cost equal to your Intelligence Supported Skills deal 8% more non-Ailment Damage over time per 100 IntelligencePlace 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.	Minion Pact IIMinion Pact IISupport, Minion Category: Minion Pact Tier: 4Support Requirements: +5 IntSupports damaging skills you use yourself, draining the life from one of your Minions on use in order to boost the skill's damage. Only takes effect if you have a Minion with enough life to drain the full amount.Supported Skills remove 150% of your maximum Life from a nearby Minion on use to 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.
V	Chaos MasteryChaos MasterySupport, Chaos Category: Mastery Tier: 5Support Requirements: +5 IntSupports Chaos skills, granting them an additional level. Does not support skills which do not have levels.+1 to Level of Supported Chaos 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.	Profanity IIProfanity IISupport, Chaos Category: Profanity Tier: 5Support Requirements: +5 IntSupports Skills you use yourself. Supported Skills consume many Corpses on use, dealing more Chaos Damage per Corpse consumed. Cannot support Triggered Skills or Reservation Skills.Supported Skills consume up to 10 Corpses within 5 metres on use, if possible Supported Skills deal 5% more Chaos Damage for each Corpse consumed this wayPlace 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

Contagion has restrictions on where or how it can drop.

It can be obtained by engraving an Uncut Skill Gem.

Alternate skill effects

Contagion has the following alternate skill effects:

Item	Description

Version history

Version	Changes
0.3.0	The base damage scaling of all player spell and secondary damage skills has been tweaked to scale better in the late game. Generally speaking, spells that do not have damage number changes called out below will have near-identical base damage at low levels, roughly 5% more damage at gem level 20, and roughly 20% more damage at gem level 30. Contagion: Quality now provides Contagion targets 0-2 additional Enemies when Cast, instead of +0-100% to Maximum Debuff Damage bonus from spreading.
0.2.1	Added "Barrageable" gem tag.[Undocumented]
0.2.0	Many Skills have had their base damage and/or damage growth per level rebalanced. Most of these changes are not specifically mentioned below as the changes are too widespread.
0.1.0e	Increased the damage growth per level on Essence Drain, Contagion, Profane Ritual and Chaos Bolt (Wand Skill). Results in approximately 33% more damage at Gem Level 25.
0.1.0d	Fixed a bug where the Contagion Skill was not spreading Poison.
0.1.0	Introduced to the game.