Contagion

ContagionSpell, AoE, Duration, Chaos
Level: (1-20)
Cost: (5-20) Mana
Cast Time: 0.60 sec
AoE Radius: 20Requires Level 4Unleashes a vile contagion on enemies, dealing chaos damage over time. If an enemy dies while affected by Contagion, the debuff spreads to other enemies.Deals (3.5-235.9) Base Chaos Damage per second
Base duration is 5.00 seconds
Modifiers to Spell Damage apply to this Skill's Damage Over Time effect
Base radius is 1.7 metres
Spreads when affected Enemy dies

Additional Effects From 1-20% Quality:
Base radius is (0.01-0.2) metresPlace into an item socket of the right colour to gain this skill. Right click to remove from a socket.

Acquisition
Drop level: 5Metadata
Item class: Skill Gem
Metadata ID: Metadata/Items/Gems/SkillGemContagion

Contagion is a chaos spell that applies a chaos damage over time effect to all enemies in the area, and spreads itself when an enemy dies. Contagion interacts favourably with Essence DrainEssence DrainSpell, Projectile, Duration, Chaos, AoE
Level: (1-20)
Cost: (8-23) Mana
Cast Time: 0.70 sec
Critical Strike Chance: 5.00%
Effectiveness of Added Damage: 160%Requires Level 12Fires a projectile that applies a damage over time debuff when it hits. You are healed for a portion of the debuff damage. The debuff is spread by Contagion.Deals (12-776) to (18-1164) Chaos Damage
Deals (42.2-1818.1) Base Chaos Damage per second
Base duration is 3.80 seconds
Modifiers to Spell Damage apply to this Skill's Damage Over Time effect
Regenerate 0.50% of Debuff Damage as Life

Additional Effects From 1-20% Quality:
Regenerate +(0.025-0.5)% of Debuff Damage as LifePlace into an item socket of the right colour to gain this skill. Right click to remove from a socket., a skill that deals heavy chaos damage over time and is spread by Contagion.

Skill functions and interactions

• Modifiers to Spell Damage apply to this skill's Damage Over Time Effect: Modifiers to spell damage only affect the damage over time effect of Contagion granted by the gem and do not affect other sources of damage over time caused by the skill.

• Essence DrainEssence DrainSpell, Projectile, Duration, Chaos, AoE
  Level: (1-20)
  Cost: (8-23) Mana
  Cast Time: 0.70 sec
  Critical Strike Chance: 5.00%
  Effectiveness of Added Damage: 160%Requires Level 12Fires a projectile that applies a damage over time debuff when it hits. You are healed for a portion of the debuff damage. The debuff is spread by Contagion.Deals (12-776) to (18-1164) Chaos Damage
  Deals (42.2-1818.1) Base Chaos Damage per second
  Base duration is 3.80 seconds
  Modifiers to Spell Damage apply to this Skill's Damage Over Time effect
  Regenerate 0.50% of Debuff Damage as Life
  
  Additional Effects From 1-20% Quality:
  Regenerate +(0.025-0.5)% of Debuff Damage as LifePlace into an item socket of the right colour to gain this skill. Right click to remove from a socket.: When an enemy affected by both Contagion and Essence Drain dies, the resulting Contagion proc will spread both effects. Contagion will not spread other damage over time effects.
  • This also applies to Blight of ContagionBlight of ContagionSpell, Chaos, AoE, Channelling, Duration
    Level: (1-20)
    Cost: (2-5) Mana
    Cast Time: 0.25 secApply a debuff to enemies in front of you which deals chaos damage over time. Enemies who aren't already debuffed by Blight are also hindered for a shorter secondary duration, slowing their movement. Continued channelling adds layers of damage to the debuff, each with their own duration. The damaging debuff is spread by Contagion.Deals (9.7-704.3) Base Chaos Damage per second
    Base duration is 4.00 seconds
    Base secondary duration is 1.00 seconds
    Modifiers to Spell Damage apply to this Skill's Damage Over Time effect
    +(0-0.6) metres to radius
    80% reduced Movement Speed
    Debuff can have up to 5 layers of Damage
    
    Additional Effects From 1-20% Quality:
    Base duration is (0.05-1) secondsPlace into an item socket of the right colour to gain this skill. Right click to remove from a socket. and Essence Drain of DesperationEssence Drain of DesperationSpell, Projectile, Duration, Chaos, AoE
    Level: (1-20)
    Cost: (8-23) Mana
    Cast Time: 0.70 sec
    Critical Strike Chance: 5.00%
    Effectiveness of Added Damage: 160%Requires Level 12Fires a projectile that applies a damage over time debuff when it hits. You lose Life and Energy Shield equal to a portion of the debuff damage. The debuff is spread by Contagion.Deals (12-776) to (18-1164) Chaos Damage
    Deals (91.5-3959.4) Base Chaos Damage per second
    Base duration is 3.80 seconds
    Modifiers to Spell Damage apply to this Skill's Damage Over Time effect
    Lose Life and Energy Shield equal to 0.3% of Debuff Damage
    
    Additional Effects From 1-20% Quality:
    Base duration is (0.02-0.4) secondsPlace into an item socket of the right colour to gain this skill. Right click to remove from a socket..

• Duration: Increases and reductions to duration function normally. The duration of Contagion and associated degeneration effects (Essence DrainEssence DrainSpell, Projectile, Duration, Chaos, AoE
  Level: (1-20)
  Cost: (8-23) Mana
  Cast Time: 0.70 sec
  Critical Strike Chance: 5.00%
  Effectiveness of Added Damage: 160%Requires Level 12Fires a projectile that applies a damage over time debuff when it hits. You are healed for a portion of the debuff damage. The debuff is spread by Contagion.Deals (12-776) to (18-1164) Chaos Damage
  Deals (42.2-1818.1) Base Chaos Damage per second
  Base duration is 3.80 seconds
  Modifiers to Spell Damage apply to this Skill's Damage Over Time effect
  Regenerate 0.50% of Debuff Damage as Life
  
  Additional Effects From 1-20% Quality:
  Regenerate +(0.025-0.5)% of Debuff Damage as LifePlace into an item socket of the right colour to gain this skill. Right click to remove from a socket.) is not reset when spread to other enemies on death.

• Area of Effect: Modifiers to area of effect affect both the skill radius and spread radius of Contagion. Modifiers to area damage (such as Concentrated Effect SupportConcentrated Effect SupportSupport, AoE
  Icon: o
  Level: (1-20)
  Cost & Reservation Multiplier: 140%Requires Level 18Supports any skill with an area of effect, regardless of whether that skill deals damage.Supported Skills deal (25-39)% more Area Damage
  Supported Skills have 30% less Area of Effect
  
  Additional Effects From 1-20% Quality:
  Supported Skills deal (0.5-10)% increased Area DamageThis is a Support Gem. It does not grant a bonus to your character, but to skills in sockets connected to it. Place into an item socket connected to a socket containing the Skill Gem you wish to augment. Right click to remove from a socket.) do not apply.

• On hit effects: Contagion does not hit, and therefore cannot activate the effects of supports such as Hextouch SupportHextouch SupportSupport, Hex, Trigger
  Icon: &
  Level: (1-20)
  Cost & Reservation Multiplier: 130%Requires Level 38Must support both a skill that hits enemies, and a hex curse skill to work. The hex will be applied when enemies are hit by the other skill. Cannot support totems, traps, or mines. Minions cannot apply hexes this way.Supported Skills apply supported Curses on Hit
  You cannot Cast Supported Curse Spells
  35% less Effect of Supported Curses
  Supported Skills have (50-31)% reduced Curse Duration
  
  Additional Effects From 1-20% Quality:
  Supported Skills have (0.5-10)% increased Curse DurationThis is a Support Gem. It does not grant a bonus to your character, but to skills in sockets connected to it. Place into an item socket connected to a socket containing the Skill Gem you wish to augment. Right click to remove from a socket..

Gem level progression

Level				Mana Cost	Chaos Damage per sec	Exp.	Total Exp.
1	4	0	0	5	3.5	0	0
2	6	0	0	6	4.3	841	841
3	9	0	17	6	5.7	3099	3940
4	12	14	21	7	7.4	7433	11373
5	16	18	26	8	10.2	22895	34268
6	20	22	31	9	13.6	49725	83993
7	24	25	37	10	18	95714	179707
8	28	29	42	11	23.3	169595	349302
9	32	33	47	11	29.9	283759	633061
10	36	36	52	12	38.1	453996	1087057
11	40	40	58	13	48.1	703128	1790185
12	44	44	63	14	60.3	1061223	2851408
13	48	48	68	15	75.2	2065870	4917278
14	52	51	74	16	93.3	2507110	7424388
15	55	54	78	16	109.5	2573731	9998119
16	58	57	82	17	128.1	7611351	17609470
17	61	60	86	18	149.6	13437908	31047378
18	64	62	90	18	174.4	25052147	56099525
19	67	65	94	19	203	43869436	99968961
20	70	68	98	20	235.9	242081178	342050139
21	72	70	100	20	260.5	—	—
22	74	—	—	21	287.5	—	—
23	76	—	—	21	317.2	—	—
24	78	—	—	21	349.7	—	—
25	80	—	—	22	385.4	—	—
26	82	—	—	22	424.5	—	—
27	84	—	—	23	467.3	—	—
28	86	—	—	23	514.3	—	—
29	88	—	—	24	565.7	—	—
30	90	—	—	24	621.9	—	—
31	91	—	—	24	652	—	—
32	92	—	—	25	683.5	—	—
33	93	—	—	25	716.5	—	—
34	94	—	—	25	750.9	—	—
35	95	—	—	25	787	—	—
36	96	—	—	25	824.7	—	—
37	97	—	—	26	864.1	—	—
38	98	—	—	26	905.4	—	—
39	99	—	—	26	948.5	—	—
40	100	—	—	26	993.6	—	—

Item acquisition

Contagion can drop anywhere.

Recipes

Contagion can be created from the following recipes:

Amount	Part	Description	Meta
3	The Bitter BlossomThe Bitter Blossom3Level 21 Chaos Gem Quality: +23% CorruptedThe pain you feel is of no consequence, it is evolution, to be made whole within something greater.	Random corrupted level 21 Chaos gem with 23% quality	A
13	The CataclysmThe Cataclysm13Level 21 Spell Gem CorruptedThe mighty warriors traded in blows, the nimble archers in arrows, yet it was the brazen thaumaturgists who would bring catastrophe to all.	Random corrupted level 21 Spell gem	A
6	The FoxThe Fox6Level 20 Gem"Masters of wit, strength and cunning. To survive the harsh winters, you must be like the fox." - Ezomyte Proverb	Random level 20 gem	A
3	Gemcutter's PromiseGemcutter's Promise3Gem Quality: +20%"I swore to use my position to help the people. What good is power when it just accumulates on the already-powerful?" - Erasmus, Imperial Gemcutter	Random gem with 20% quality	A
1	Gemcutter's IncubatorGemcutter's IncubatorStack Size: 10Adds an incubated Quality Gem item to an equippable item Item drops after killing {0} monstersRight click this item then left click an item to apply it. The Incubated item drops after killing a specific number of monsters.	Random gem with 1–20% quality	A
1	The VoidThe Void1Reach into the Void and claim your prize.	Random divination card set exchange	A

Quest reward

This item is given as a quest reward for the following quests:

Class →	Witch	Shadow	Ranger	Duelist	Marauder	Templar	Scion
Quest ↓
Breaking Some Eggs Act 1

Vendor reward

This item can be bought at the listed NPC vendors, after completing the following quests:

Class →	Witch	Shadow	Ranger	Duelist	Marauder	Templar	Scion
Quest ↓
Breaking Some Eggs Act 1 Nessa
A Fixture of Fate Act 3 Siosa
Fallen from Grace Act 6 Lilly Roth

Related helmet enchantments

The following helmet enchantments affect Contagion.

Note that helmet enchantments are no longer obtainable since version 3.23.0 and can only be obtained in permanent leagues as already enchanted items from before this patch.

Name		Labyrinth	Stats	Spawn Weighting
Enchantment Contagion Damage 1	66	Merciless Labyrinth	25% increased Contagion Damage	helmet 100
Enchantment Contagion Damage 2	75	Eternal Labyrinth	40% increased Contagion Damage	helmet 100
Enchantment Contagion Duration 1	66	Merciless Labyrinth	20% increased Contagion Duration	helmet 100
Enchantment Contagion Duration 2	75	Eternal Labyrinth	30% increased Contagion Duration	helmet 100
Enchantment Contagion Radius 1	66	Merciless Labyrinth	16% increased Contagion Area of Effect	helmet 100
Enchantment Contagion Radius 2	75	Eternal Labyrinth	24% increased Contagion Area of Effect	helmet 100

Alternate skill effects

Contagion has the following alternate skill effects:

Item	Description
Arcane Contagion EffectArcane Contagion EffectSkill Gem EffectYour Contagion becomes a blue arcane effect.	Your Contagion becomes a blue arcane effect.
Celestial Contagion EffectCelestial Contagion EffectSkill Gem EffectYour Contagion becomes a Celestial Effect.	Your Contagion becomes a Celestial Effect.
Project Contagion EffectProject Contagion EffectSkill Gem EffectYour Contagion becomes a Project Effect.	Your Contagion becomes a Project Effect.
Scientist Contagion EffectScientist Contagion EffectSkill Gem EffectYour Contagion becomes a Scientist Effect.	Your Contagion becomes a Scientist Effect.
Sunprism Contagion EffectSunprism Contagion EffectSkill Gem EffectYour Contagion becomes a Sunprism Effect.	Your Contagion becomes a Sunprism Effect.

Version history

Version	Changes
3.23.0	Quality now provides +0-0.2 metres to radius, instead of 0-10% increased Area of Effect.
3.13.0	Now has a base radius of 17 (from 20).
3.12.0	Now has alternative quality.
3.8.0	No longer gains additional radius as the gem levels (previously gained +4 radius by gem level 20).
3.6.0	Mana Cost at gem level 1 is now 5 (was 11). Mana Cost at gem level 20 is now 20 (was 28). Can now affect up to 40 targets per cast (from 20).
2.6.0	Contagion's radius has increased from 18 to 20 units.
2.2.1d	Fixed an instance crash with Contagion.
2.1.1c	Fixed an instance crash with [...] Contagion.
2.1.1b	Fixed a bug where Contagion could be cast and spread through walls.
2.1.1	Contagion can now be supported by Iron Will.
2.1.0	Added to the game.