Caustic Arrow

Caustic ArrowAttack, Projectile, AoE, Duration, Chaos, Bow
Radius: 20
Mana Cost: (6-10)
Cast Time: 1.00 sec
Effectiveness of Added Damage: (55%-64%)
Projectile Speed: 3260Fires an arrow which deals chaos damage in an area on impact, and spreads caustic ground. Enemies standing on the caustic ground take chaos damage over time.Per 1% Quality:
0.5% increased Area of EffectDeals (55-64.4)% of Base Attack Damage
Base duration is 2 seconds
Deals (8.8-1927.1) Base Chaos Damage per second
60% of Physical Damage Converted to Chaos Damage
Modifiers to Projectile Damage apply to this Skill's Damage Over Time effect
+(0-6) to radiusPlace into an item socket of the right colour to gain this skill. Right click to remove from a socket.Acquisition
Level: 5Purchase Costs

Normal

1x Scroll of Wisdom

Sell Price
1x Scroll FragmentMiscellaneous
Item class: Active Skill Gems
Metadata ID: Metadata/Items/Gems/SkillGemPoisonArrow

Caustic Arrow is a bow attack that fires an arrow dealing chaos damage and spreading caustic ground. Enemies standing within it receive a debuff that deals chaos damage over time. Caustic ground does not poison and is therefore not affected by poison-related modifiers.

Skill functions and interactions

• Caustic Arrow will explode either at the targeted location or on the first monster or obstacle it hits.

• Multiple projectiles: firing additional projectiles can spread caustic ground over a wider area, but the damage over time from overlapping patches of caustic ground does not stack.

• Piercing: piercing Caustic Arrow projectiles will spread caustic ground each time they hit and will receive the chaos damage bonus any time they impact an enemy.

• Projectile damage: passive nodes and gems (such as Slower Projectiles SupportSlower Projectiles SupportSupport, Projectile
  Icon: J
  Mana Multiplier: 140%Requires Level 31Supports projectile skills.Per 1% Quality:
  Supported Skills deal 0.5% increased Projectile DamageSupported Skills have (20-30)% less Projectile Speed
  Supported Skills deal (20-29)% more Projectile 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 Active Skill Gem you wish to augment. Right click to remove from a socket.) that increase projectile damage will increase both the damage on hit and the area of effect damage.

• Concentrated Effect: Concentrated Effect SupportConcentrated Effect SupportSupport, AoE
  Icon: o
  Mana Multiplier: 140%Requires Level 18Supports any skill with an area of effect, regardless of whether that skill deals damage.Per 1% Quality:
  Supported Skills deal 0.5% increased Area DamageSupported Skills have 30% less Area of Effect
  Supported Skills deal (35-54)% more 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 Active Skill Gem you wish to augment. Right click to remove from a socket. decreases the size of the AoE and increase its damage. However, due to the nature of the skill and the wording of its modifiers, the damage increase will not appear on the tooltip.

• Point Blank: Point Blank does not affect the damage from caustic ground; it only affects projectile attack damage.

• Iron Grip: The strength bonus from the Iron Grip keystone passive does not affect the damage from caustic ground because it is not considered an attack nor is it based on physical damage. The increased projectile damage portion of the Iron Grip SupportIron Grip SupportProjectile, Physical, Support
  Icon: iRequires Level 18Supports attack skills that fire projectiles, making the increase to physical melee damage from strength also increase their physical projectile damage.Per 1% Quality:
  Supported Skills deal 0.5% increased Projectile DamageStrength's damage bonus applies to Projectile Attacks made with Supported Skills
  Supported Skills deal (0-38)% increased Projectile 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 Active Skill Gem you wish to augment. Right click to remove from a socket. will increase the damage from caustic ground, but the strength bonus the support gem shares with the keystone will not apply.

• Accuracy: The projectile attack is subject to accuracy and can miss. However, the explosion will spread caustic ground and do damage regardless of whether the projectile attack hits or misses. Piercing Caustic Arrow will not spread caustic ground if it misses.

• Duration: modifiers to duration will affect the duration of the caustic ground.

• Culling strike: The increased damage from Culling Strike SupportCulling Strike SupportSupport
  Icon: X
  Mana Multiplier: 110%Requires Level 18Supports any skill that hits enemies. If enemies are left below 10% of maximum life after being hit by these skills, they will be killed.Per 1% Quality:
  Supported Skills have 0.5% increased Attack Speed
  Supported Skills have 0.5% increased Cast SpeedKill Enemies that have 10% Life or lower when Hit by Supported Skills
  Supported Skills deal (0-38)% increased 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 Active Skill Gem you wish to augment. Right click to remove from a socket. applies to the damage from caustic ground, but the caustic ground will not kill enemies instantly when they have less than 10% life.

• Curses: Sniper's MarkSniper's MarkSpell, AoE, Duration, Curse
  Radius: 22
  Mana Cost: (16-33)
  Cast Time: 0.50 secRequires Level 24Curses all targets in an area, making them easier to pierce and to knock back, and increasing the damage they take from projectiles.Per 1% Quality:
  Cursed enemies take 0.5% increased Damage from Projectile HitsBase duration is (9-10.9) seconds
  Projectiles Pierce Cursed Enemies
  Hits on Cursed Enemies have an additional 25% chance to Knockback
  Cursed enemies take (25-44)% increased Damage from Projectile Hits
  +(0-10) to radiusPlace into an item socket of the right colour to gain this skill. Right click to remove from a socket. requires the target to be hit. The caustic ground won't be affected by it.^{[confirmation needed because of 3.12 change]} DespairDespairSpell, AoE, Duration, Curse, Chaos
  Radius: 22
  Mana Cost: (16-33)
  Cast Time: 0.50 secRequires Level 24Curse all targets in an area, making them less resistant to chaos damage and causing them to take increased damage over time. Cursed enemies also take additional chaos damage when hit.Per 1% Quality:
  Cursed enemies take 0.5% increased Damage from Damage Over Time effectsBase duration is (9-10.9) seconds
  Cursed enemies have -(20-29)% to Chaos Resistance
  Cursed enemies take (15-25)% increased Damage from Damage Over Time effects
  Adds (9-46) to (12-57) Chaos Damage to Hits against Cursed Enemies
  +(0-10) to radiusPlace into an item socket of the right colour to gain this skill. Right click to remove from a socket. does affect the caustic ground.

Gem level progression

Level			Mana Cost	Damage Effectiveness	Damage Multiplier	Chaos Damage per sec	Radius	Exp.	Total Exp.
1	1	0	6	55%	55%	8.8	N/A	0	0
2	2	0	6	55%	55.5%	10.1	N/A	70	70
3	4	16	6	56%	56%	13.1	1	308	378
4	7	22	6	56%	56.5%	18.4	1	1,554	1,932
5	11	31	7	57%	57%	27.8	1	6,667	8,599
6	16	41	7	57%	57.5%	44	2	26,047	34,646
7	20	50	7	58%	58%	61.9	2	49,725	84,371
8	24	58	7	58%	58.5%	85.4	2	95,714	180,085
9	28	67	8	59%	59%	116.2	3	169,595	349,680
10	32	75	8	59%	59.5%	156.3	3	283,759	633,439
11	36	83	8	60%	59.9%	208.5	3	453,996	1,087,435
12	40	92	8	60%	60.4%	275.9	3	703,128	1,790,563
13	44	100	9	61%	60.9%	362.7	4	1,061,223	2,851,786
14	48	109	9	61%	61.4%	474.1	4	2,065,870	4,917,656
15	52	117	9	62%	61.9%	616.9	4	2,507,110	7,424,766
16	56	125	9	62%	62.4%	799.3	5	5,798,936	13,223,702
17	60	134	10	63%	62.9%	1031.8	5	15,083,919	28,307,621
18	64	142	10	63%	63.4%	1327.6	5	27,792,735	56,100,356
19	67	148	10	64%	63.9%	1600.8	6	43,869,739	99,970,095
20	70	155	10	64%	64.4%	1927.1	6	242,081,556	342,051,651
21	72	159	11	65%	64.9%	2179.2	6	N/A	N/A
22	74	N/A	11	65%	65.4%	2462.7	7	N/A	N/A
23	76	N/A	11	66%	65.9%	2781.5	7	N/A	N/A
24	78	N/A	11	66%	66.4%	3139.9	7	N/A	N/A
25	80	N/A	12	67%	66.9%	3542.6	8	N/A	N/A
26	82	N/A	12	67%	67.4%	3995	8	N/A	N/A
27	84	N/A	12	68%	67.9%	4503.1	8	N/A	N/A
28	86	N/A	12	68%	68.4%	5073.4	9	N/A	N/A
29	88	N/A	13	69%	68.9%	5713.4	9	N/A	N/A
30	90	N/A	13	69%	69.4%	6431.6	9	N/A	N/A
31	91	N/A	13	70%	69.8%	6822.8	9	N/A	N/A
32	92	N/A	13	70%	70.3%	7237.1	10	N/A	N/A
33	93	N/A	14	71%	70.8%	7675.8	10	N/A	N/A
34	94	N/A	14	71%	71.3%	8140.3	10	N/A	N/A
35	95	N/A	14	72%	71.8%	8632.2	11	N/A	N/A
36	96	N/A	14	72%	72.3%	9152.9	11	N/A	N/A
37	97	N/A	15	73%	72.8%	9704.1	11	N/A	N/A
38	98	N/A	15	73%	73.3%	10287.7	12	N/A	N/A
39	99	N/A	15	74%	73.8%	10905.4	12	N/A	N/A
40	100	N/A	15	74%	74.3%	11559.3	12	N/A	N/A

Item acquisition

Upgrade paths

This item can be acquired through the following upgrade paths or vendor recipes:

Amount	Ingredient	General Notes	Type
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	Automatic
3	Gemcutter's PromiseGemcutter's Promise3Superior Gem 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 superior gem (Q20)	Automatic

Quest reward

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

Class →	Witch	Shadow	Ranger	Duelist	Marauder	Templar	Scion
Quest ↓
Enemy at the Gate 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 ↓
Enemy at the Gate 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 Caustic Arrow.

Name		Stats	Spawn Weighting
Enchantment Caustic Arrow Damage 1	66	25% increased Caustic Arrow Damage	helmet 75 default 0
Enchantment Caustic Arrow Damage 2	75	40% increased Caustic Arrow Damage	helmet 75 default 0
Enchantment Caustic Arrow Duration 1	66	20% increased Caustic Arrow Duration	helmet 75 default 0
Enchantment Caustic Arrow Duration 2	75	30% increased Caustic Arrow Duration	helmet 75 default 0
Enchantment Caustic Arrow Area Of Effect 1	66	16% increased Caustic Arrow Area of Effect	helmet 75 default 0
Enchantment Caustic Arrow Area Of Effect 2	75	24% increased Caustic Arrow Area of Effect	helmet 75 default 0
Enchantment Caustic Arrow Wither On Hit 1	66	Caustic Arrow has 14% chance to inflict Withered on Hit for 2 seconds base Duration	helmet 75 default 0
Enchantment Caustic Arrow Wither On Hit 2	75	Caustic Arrow has 20% chance to inflict Withered on Hit for 2 seconds base Duration	helmet 75 default 0

Alternate skill effects

Caustic Arrow has the following alternate skill effects:

Item	Effect(s)
Celestial Caustic Arrow EffectCelestial Caustic Arrow EffectSkill Gem EffectYour Caustic Arrow becomes a Celestial Effect.	Your Caustic Arrow becomes a Celestial Effect.
Tentacle Caustic Arrow EffectTentacle Caustic Arrow EffectSkill Gem EffectYour Caustic Arrow becomes an area of ethereal purple tentacles.	Your Caustic Arrow becomes an area of ethereal purple tentacles.

Version history

Version	Changes
3.9.0	Now deals 8.8 base Chaos Damage per second at gem level 1 (from 7), up to 1927.1 at gem level 20 (from 1714.8). Now gains additional radius as the gem levels, up to +6 at gem level 20 (from +3).
3.6.0	Caustic Arrow's hit now deals 30% less damage against players (previously had no penalty).
3.0.0	Caustic Arrow's damage over time grows more quickly as it levels, up to 765 base Chaos damage per second at gem level 20 (up from 550.3). It is also now modified by projectile damage modifiers.
2.6.0	Caustic Arrow gains 1 additional unit of radius every 5 levels. No longer gain increased area of effect radius.
2.1.0	Poison Arrow has been renamed to Caustic Arrow as part of the poison changes. The damage of this skill has been increased by around 37% at level 1, but reduced by around 42% by level 20. This reduction is more than compensated for by supporting the skill with the new supports. Caustic Arrow's mana costs have been increased, from 5 to 8 at level one, and from 13 to 16 at level 20.
2.0.0	Reduced the mana cost across all levels. Now grants 0.5% increased area of effect radius per 1% of quality (was 1% per 1% quality). Damage increased by approximately 26% at gem level 20.
1.3.0	Poison Arrow can now damage totems.
1.1.2	Damage has been increased by 8% at level 1, scaling up to an increase of 75% at level 15 of the gem.
1.0.6	Poison Arrow's damage has been increased at higher levels. It now does roughly 35% more damage at gem level 15.
1.0.3	Damage progression has been increased. It is now around 15% better at level 15 than it was in 1.0.2.
1.0.2	Early levels of Poison Arrow have had their damage reduced by around 35%.
0.9.13	It now starts off around 85% stronger at level 1 and is about 1% weaker at level 15.
0.9.12	Rebalanced its mana cost progression to reflect the fact that it does damage in a comparable way to Spells.
0.9.9	The size of the Poison Arrow clouds now scale with their Area of Effect radius properly.
0.9.7	Improved the effects of Poison Arrow.
0.9.5g	Fixed a bug where the Poison Arrow cloud would appear where you clicked even if the arrow was stopped before then by a wall.
0.9.5	Fixed Poison Arrow so that damage from the degeneration is scaled properly for PvP.
0.9.4	Increased the damage.
0.9.2	Poison Arrow does more damage at higher levels than before.
0.8.7	Poison Arrow does additional chaos damage on the actual arrow itself now, in addition to the cloud damage.
0.8.5	Added new skill prototype: "Poison Arrow" (Fires an arrow which explodes in a cloud of poison. Enemies who enter the cloud are poisoned for a short time, taking chaos damage)