Blight (game mechanic)

Blights are tower defence-like encounters that can spawn from Fungal Growths in any map area (as well as The Sewers and The Imperial Gardens in the campaign), which will always be accompanied by Sister Cassia. This encounter is considered Extra Content and has a baseline greater than 8% chance to appear in any non-unique map area.

Blight encounters are also found in Blighted maps, which are a modified version of existing maps, which contains no regular monsters and instead contains a single Blight encounter. Blights in Blighted maps are far larger, spawn a significantly increased amount of enemies and bosses, and provide a greater quantity and variety of rewards. Players can trade Blighted maps. Atlas passives that affect Blight encounters in maps do not affect Blighted maps. There is also a pinnacle version of Blighted maps called Blight-ravaged maps.

Mechanics

Once players interact with the Fungal Growth, Cassia will place a purification pump on the growth, causing it to spawn roots in random directions. At the end of each root is a portal that spawns enemies that slowly move towards the core, only stopping to attack units in its way. The Blight can spawn up to 8 roots, increasing with zone level. Players will be given a short preparation time before the Blight starts spawning monsters. Players can skip this by pressing a button that appears on the bottom right during this preparation period.

Some roots will spawn after a delay, and sometimes a root will have multiplied monster density (indicated by a multiplier) or contains a Blight boss (indicated by an icon on top). An icon corresponding to a tower can appear over each root, indicating which tower it is resistant to. Along the paths of the roots, players can construct a tower in specified areas. Towers cost resources to build or upgrade, which are given at the start and also acquired from killing blighted enemies. In a party, a tower belongs to the player who built or last upgraded it, using that player's ring anointments.^[1]

When an enemy reaches the core, it will lower the pump's durability by a fixed amount and despawn. The pump has 10 durability in maps (20 in Blighted maps), and the amount of durability lowered is based on the monster's rarity (1 for normal, 2 for magic, 5 for rare, 10 for unique). When the pump's durability reaches 0, the Blight encounter fails and monsters will stop spawning.

Once all enemies from each portal/lane are defeated, reward chests will spawn at the location of each portal. These chests remain once spawned even if the pump is destroyed and the Blight encounter is failed. Blight encounters will have at least one lane that contains a Blight reward (Oils or Blighted map). Oil rewards chests have a baseline ~15% chance to drop a Blighted Map. Additionally, natural loot from killed monsters will drop at the pump's location. (Kills by towers are unaffected by any player's increases to item quantity or rarity.)

A maximum of one Blight can spawn per zone naturally; this maximum is shared between the random chance to spawn a Blight, and guaranteed Blight from Blight Scarabs, implicit map mods, enchantments, and the map device craft.^[2]

The Scarab cannot be used in combination with the map device craft.

Characters must complete least one map Blight encounter in a new league to complete Cassia's quest before she will anoint items. This also applies to the Blight Stash Tab.

Strategy

The most important thing to do in a Blight encounter is to keep the minions stalled. If you leave a lane unprotected, you'll have to scramble to defend the pump on your own, which takes away time for you to put down towers. Prioritize building stalling towers (Chilling, Seismic, Summoning) over damage towers (Fireball, Shock Nova) first and have them covered by Empowering Towers whenever possible. An empowered Tier 3 Chilling and/or Seismic tower is usually enough to hold down a lane. Tier 4 stalling towers are not that much better at defending than their Tier 3 counterparts. If the Blight encounter has delayed lanes, try to wait until them to spawn in to see if you can get a good tower spawn in a chokepoint. Be sure to account for enemy tower resistances.

Damaging towers are more valuable in Blighted maps than small Blight encounters. Meteor Towers synergize well with stalling towers and are very effective at clearing enemies once you have your defences established. Other damage towers aren't as damaging, but are effective in the right positions. They are significantly better as Tier 4 towers than Tier 3.

Due to the way off-screen entities behave, it is advised to not move too far away from the Ichor Pump nor build towers too far away from it, as it can possibly cause enemies to leak, even if they would normally be stun-locked.

When farming Blight, especially in "juiced" maps, avoid running maps with modifiers that give monsters too much movement speed or slow/stun resistance like Monsters cannot be Stunned and Monsters' Action Speed cannot be modified to below Base Value, which limit your ability to stall and requires a high-power clear build to compensate.

For ring anointments, Your Chilling Towers freeze enemies for 0.2 seconds while they are affected by chilling beams (Opalescent/Silver) is often considered to be one of the best in the game. Other generally good or budget ring anointments include:

Your Meteor Towers create Burning Ground for 3 seconds on Hit (Indigo/Violet) (This burning ground ignores resilience to fire towers)
Your Meteor Towers drop an additional Meteor (Verdant/Opalescent)
Your Freezebolt Tower deal full damage to Cold Enemies (Verdant/Crimson)
Your Scout Towers have 25% increased Range (Teal/Violet)
Your Empowering Towers have 25% increased Effect (Sepia/Azure)

Towers

List of towers

Name	Tier	Cost	Radius	Description
Arc Tower	IV	500	45	Damage: Medium Casts Arc Ineffective against Blighted Monsters of the same type
Chilling Tower Mk I	I	100	35	Damage: Low Chills and Damages nearby enemies Ineffective against Blighted Monsters of the same type
Chilling Tower Mk II	II	150	35	Increased Damage Increased effect of Chill Affects more Targets
Chilling Tower Mk III	III	300	35	Increased Damage Increased effect of Chill Affects more targets
Empowering Tower Mk I	I	100	35	Improves the effectiveness of other Towers Does not Damage Enemies
Empowering Tower Mk II	II	150	45	Improves the effectiveness of other Towers Does not Damage Enemies
Empowering Tower Mk III	III	300	55	Improves the effectiveness of other Towers Does not Damage Enemies
Fireball Tower Mk I	I	100	45	Damage: Medium Casts a Fireball Ineffective against Blighted Monsters of the same type
Fireball Tower Mk II	II	150	60	Casts 3 Fireballs
Fireball Tower Mk III	III	300	75	Casts 5 Fireballs
Flamethrower Tower	IV	500	45	Damage: High Casts a stream of Fire Ineffective against Blighted Monsters of the same type
Freezebolt Tower	IV	500	75	Damage: Very High Shoots a Piercing projectile which Freezes enemies Ineffective against Blighted Monsters of the same type
Glacial Cage Tower	IV	500	60	Deals no Damage Imprisons Enemies Ineffective against Blighted Monsters of the same type
Imbuing Tower	IV	500	55	Improves the effectiveness of Players in range. Does not Damage Enemies
Lightning Storm Tower	IV	500	45	Damage: High Lightning rapidly strikes around the Tower Ineffective against Blighted Monsters of the same type
Meteor Tower	IV	500	100	Damage: Very High Rains Meteors from the sky Ineffective against Blighted Monsters of the same type
Scout Tower	IV	500	75	Summons 10 Flying Minions Minion Damage: High Minion Life: Low Can only summon Minions when previous Minions are dead Ineffective against Blighted Monsters of the same type
Seismic Tower Mk I	I	100	45	Damage: Low Repeats 3 times Always Stuns Damages and Stuns nearby Enemies Ineffective against Blighted Monsters of the same type
Seismic Tower Mk II	II	150	45	Repeats 5 times
Seismic Tower Mk III	III	300	45	Repeats 7 times
Sentinel Tower	IV	500	45	Summons 1 Durable Minion Minion Damage: Low Minion Life: High Can only summon Minions when previous Minions are dead Ineffective against Blighted Monsters of the same type
Shock Nova Tower Mk I	I	100	20	Damage: Low Creates Shocked Ground Casts Shock Nova Ineffective against Blighted Monsters of the same type
Shock Nova Tower Mk II	II	150	25	Increased Damage Increased chance to Shock Increased Area of Effect
Shock Nova Tower Mk III	III	300	30	Increased Damage Increased chance to Shock Increased Area of Effect
Smothering Tower	IV	500	55	Weakens Enemies in range Does not Damage Enemies
Stone Gaze Tower	IV	500	45	Periodically Petrifies Monsters Does not Damage Enemies Ineffective against Blighted Monsters of the same type
Summoning Tower Mk I	I	100	30	Summons 3 Minions Minion Damage: Low Minion Life: Low Can only summon Minions when previous Minions are dead Ineffective against Blighted Monsters of the same type
Summoning Tower Mk II	II	150	30	Summons 5 Minions
Summoning Tower Mk III	III	300	30	Summons 7 Minions
Temporal Tower	IV	500	45	Persistently Slows Monsters Does not Damage Enemies Ineffective against Blighted Monsters of the same type
Tower Foundation		0	0	A powered base for one of Cassia's towers.

Tower upgrades

Upgrade paths
Type	Upgrades	Tier IV First Choice	Tier IV Second Choice
Chilling Tower	Increased Damage Increased effect of Chill Affects more Targets	Freezebolt Tower Increased Damage (Very High) and shoots a Piercing projectile which Freezes enemies	Glacial Cage Tower Deals no Damage and Imprisons Enemies
Empowering Tower	Increased effect area	Imbuing Tower Improves the effectiveness of Players in range	Smothering Tower Weakens Enemies in range
Fireball Tower	Increased effect area and Cast more fireballs (1-3-5)	Flamethrower Tower Increased Damage (High) and casts a stream of Fire	Meteor Tower Increased Damage (Very high) and rains Meteors from the sky
Seismic Tower	Repeats more times (3-5-7)	Stone Gaze Tower Periodically Petrifies Monsters but no longer does damage	Temporal Tower</center Persistently Slows Monsters but no longer does damage
Shock Nova Tower	Increased Damage, chance to Shock and Area of Effect	Arc Tower Increased Damage (Medium) and casts Arc	Lightning Storm Tower Increased Damage (High) and Lightning rapidly strikes around the Tower
Summoning Tower	Summons more minions (3-5-7)	Scout Tower Summons 10 Flying Minions dealing high damage	Sentinel Tower Summons one durable minion with a high life pool

Rewards

Blight pump rewards

Completing or failing a Blight encounter will cause items that would have dropped from defeated Blighted monsters to drop from the pump in a loot explosion.

Additionally, completing a Blight encounter in a Blighted map or Blight-ravaged map has a chance to drop an exclusive anointable Blight unique. The drop rates of these uniques are not affected by item quantity.

Blight chests

Completing a blighted map or a blight encounter on a regular map will grant many of the following:

Image	Type	Typical drops
	Random	Random assortment of items including armour, weapons and common currency
	Blight	Oils, small chance for rare oils like Silver OilSilver OilStack Size: 10 Oil Tier: 12Can be combined with other Oils at Cassia to Enchant Rings or Amulets, or to modify Blighted Maps., Golden OilGolden OilStack Size: 10 Oil Tier: 13Can be combined with other Oils at Cassia to Enchant Rings or Amulets, or to modify Blighted Maps. and Blighted Maps
	Currency	Common currency, can contain Chaos OrbChaos OrbStack Size: 20Reforges a rare item with new random modifiersRight click this item then left click a rare item to apply it.s Small chance for Exalted OrbExalted OrbStack Size: 20Augments a rare item with a new random modifierRight click this item then left click a rare item to apply it. Rare items can have up to six random modifiers.s, Exalted ShardExalted ShardStack Size: 20A stack of 20 shards becomes an Exalted Orb.s, Ancient ShardAncient ShardStack Size: 20A stack of 20 shards becomes an Ancient Orb.s, Divine OrbDivine OrbStack Size: 20Randomises the values of the random modifiers on an itemRight click this item then left click a magic, rare or unique item to apply it.s
	Harbinger	Harbinger's OrbHarbinger's OrbStack Size: 20Reforges a map item as another of a higher tierRight click this item then left click a map to apply it.s, Beachhead map, chance for Ancient OrbAncient OrbStack Size: 20Reforges a unique equipment as another of the same item classRight click this item then left click a unique item to apply it.s and Exalted ShardExalted ShardStack Size: 20A stack of 20 shards becomes an Exalted Orb.s
	Jewelry	Rings, Amulets, Jewels, Abyss Jewels and Belts, which may be veiled, fractured, or influenced
	Divination Cards	1 Stacked DeckStacked DeckStack Size: 20A stack of unknown divination cardsRight click to take a divination card out of the deck.
	Fossils	Fossils, Resonators
	Map Fragments	Scarabs, Sacrifice at DuskSacrifice at DuskStack Size: 10The Vaal shall never fear the setting of our sun.Can be used in a personal Map Device./Dawn/Noon/Midnight, Offering to the GoddessOffering to the GoddessIt is time for the Goddess to give her final verdict. Your fate rests in her even hands.Travel to the Aspirants' Plaza and spend this item to open the Eternal Labyrinth., Small chance for valuable map fragments
	Maps	White and yellow maps (T1 to T10). Small chance for red maps (T11+).
	Uniques	Low level unique items, small chance for unique maps and valuable uniques like Inspired LearningInspired Learning Crimson JewelRadius: SmallWith 4 Notables Allocated in Radius, When you Kill a Rare monster, you gain 1 of its Modifiers for 20 secondsIf you do not learn from a won battle then you have already lost the war.Place into an allocated Jewel Socket on the Passive Skill Tree. Right click to remove from the Socket..
	Armour	Armour, some of which may be veiled, fractured, 30 quality, or influenced
	Weapons	Weapons, some of which may be veiled, fractured, 30 quality, or influenced
	Abyss	Abyss Jewels, Stygian Vise belts
	Essences	All tiers of Essences, small chance for Deafening Essences or Essence of HorrorEssence of HorrorStack Size: 9 Essence Tier: 8Upgrades a normal item to rare or reforges a rare item, guaranteeing one property Weapon: 16% chance to gain a Power, Frenzy or Endurance Charge on Kill Gloves: Socketed Gems have +3.5% Critical Strike Chance Boots: 5% reduced Elemental Damage Taken while stationary Body Armour: You take 10% reduced Extra Damage from Critical Strikes per Endurance Charge Helmet: Socketed Gems deal 30% more Elemental Damage Shield: Chill Nearby Enemies when you Block Quiver: 8 to 12 Added Cold Damage per Frenzy Charge Amulet: (15-25)% chance to Crush on Hit Ring: 4 to 7 Added Cold Damage per Frenzy Charge Belt: Gain Alchemist's Genius when you use a FlaskRight click this item then left click a normal or rare item to apply it.
	Gems	Skill gems, which may have levels and quality. Does not contain Transfigured or Awakened gems
	Talismans	Corrupted Talismans
	Labyrinth	Offering to the GoddessOffering to the GoddessIt is time for the Goddess to give her final verdict. Your fate rests in her even hands.Travel to the Aspirants' Plaza and spend this item to open the Eternal Labyrinth.
	Ultimatum	Catalysts, small chance for valuable Fertile CatalystFertile CatalystStack Size: 10Adds quality that enhances Life and Mana modifiers on a ring, amulet or belt Replaces other quality typesRight click this item then left click a ring, amulet or belt to apply it. Has greater effect on lower item level, non-unique jewellery. The maximum quality is 20%.s and Prismatic CatalystPrismatic CatalystStack Size: 10Adds quality that enhances Resistance modifiers on a ring, amulet or belt Replaces other quality typesRight click this item then left click a ring, amulet or belt to apply it. Has greater effect on lower item level, non-unique jewellery. The maximum quality is 20%.s
	Delirium	Simulacrum SplinterSimulacrum SplinterStack Size: 300Combine 300 Splinters to create a Simulacrum.s, Cluster Jewels, Delirium orbs
	Breach	Breach Splinters, Breach RingsBreach RingProperties are doubled while in a BreachCorrupted, Breach Scarabs, and rarely Breachstones or Empowered Breachstones
	Legion	Legion Splinters, Incubators
	Scarab	Scarabs

Ruthless mode

Reward chests from Blight encounters in Ruthless mode lack reward icons, and drop generic items, oils, or Blighted maps.

Related Atlas passive skills

Atlas passives do not affect blighted maps and blight-ravaged maps.

Name	Stats
Additional Blight Chest Chance	Lanes of Blight Encounters in your Maps have 10% chance for an additional Reward Chest [1] [2]
Blight Boss Additional Reward	Blight Bosses in your Maps have 5% chance to add an additional Reward Chest when Defeated [1] [2] [3] [4]
Blight Chest Chance and Lucky Chests	Varieties of Items contained in 1 Blight Chest in your Maps are Lucky Lanes of Blight Encounters in your Maps have 5% chance for an additional Reward Chest [1]
Blight Crafting Option	5% chance on Completing your Maps to gain a free use of the Blight Map Crafting Option [1] [2]
Blight Encounter Chance	Your Maps have +12% chance to contain a Blight Encounter [1] [2] [3] [4] [5] Your Maps have +6% chance to contain a Blight Encounter [10] [11] [12] [13] [14] [15] [16] [17] [18]
Blight Monster Increased Damage Taken	Blight Monsters in your Maps take 8% increased Damage [1] [2] [3]
Blight Pack Size	Blight Encounters in your Maps spawn 8% more Non-Unique Monsters [1] [2] Blight Encounters in your Maps spawn 6% more Non-Unique Monsters [2]
Blight Tower Cost	20% reduced Cost of Building and Upgrading Towers [1] [2]
Blighted Map Reward Chance	Blight Chests in your Maps have 10% more chance to contain Blighted Maps [1] [2] [3] [4]
Cassia's Pride	Blight Monsters in your Maps take 75% less Damage from Players and their Minions Blight Towers and their Minions in your Maps deal 300% more Damage [1]
Lucky Blight Chests	8% chance for Blight Chests to contain an additional Reward Varieties of Items contained in 1 Blight Chest in your Maps are Lucky [1] [2]
Blightspawn	1 Lane of Blight Encounters in your Maps is guarded only by Blight Bosses Blight Bosses in your Maps have 10% chance to add an additional Reward Chest when Defeated [1]
Epidemiology	Varieties of Items contained in 3 Blight Chests in your Maps are Lucky Blight chests in your Maps have a 20% chance to be openable again [1]
Fungal Bloom	Your Maps have +40% chance to contain a Blight Encounter [1]
Fungal Horizons	Blight Chests in your Maps have 60% more chance to contain Blighted Maps Completing a Blight Encounter in your Maps grants all Players Blightreach [1]
Immune Response	Blight Encounters in your Maps spawn 50% more Non-Unique Monsters Blight Monsters in your Maps spawn 100% faster [1]
Sturdy Construction	Ichor Pumps in your Maps have 100% increased Durability Blight Monsters in your Maps take 12% increased Damage [1]
Templar Ingenuity	Blight Towers in your Maps can be Salvaged after the Blight Encounter Higher Tier Towers grant better Salvaged Rewards Salvaged Rewards are improved for each different Tower Type built during Encounter [1]

Related scarabs

Item	Limit	Description
Blight ScarabBlight ScarabStack Size: 20 Limit: 1Area contains a Blight EncounterThe tendrils creep and grow...Can be used in a personal Map Device to add modifiers to a Map.	1	Area contains a Blight Encounter
Blight Scarab of BloomingBlight Scarab of BloomingStack Size: 20 Limit: 1Blight Encounters in Area have up to 3 additional Unique Bosses Unique enemies in Blight Encounters have 100% increased life Tier 14+ Blighted Maps found in Area drop as Blight-Ravaged Maps insteadOnce a century, the Blight spills forth...Can be used in a personal Map Device to add modifiers to a Map.	1	Blight Encounters in Area have up to 3 additional Unique Bosses Unique enemies in Blight Encounters have 100% increased life Tier 14+ Blighted Maps found in Area drop as Blight-Ravaged Maps instead
Blight Scarab of InvigorationBlight Scarab of InvigorationStack Size: 20 Limit: 1Each Empowering Tower in Areas grants Blighted Monsters in range increased Difficulty and RewardReversing the polarity of the compression modulator seems to have intriguing effects...Can be used in a personal Map Device to add modifiers to a Map.	1	Each Empowering Tower in Areas grants Blighted Monsters in range increased Difficulty and Reward
Blight Scarab of the BlightheartBlight Scarab of the BlightheartStack Size: 20 Limit: 1Blight Encounters in Area have one Blighted Chest Blight Encounters in Area spawn many more waves of Enemies Blighted Chests in Area grow larger and more rewarding the more Blighted Enemies are slainThe core grows larger with each cycle, doomed to spill forth...Can be used in a personal Map Device to add modifiers to a Map.	1	Blight Encounters in Area have one Blighted Chest Blight Encounters in Area spawn many more waves of Enemies Blighted Chests in Area grow larger and more rewarding the more Blighted Enemies are slain

Version history

Version	Changes
3.24.0	Sources of Divination Cards drops from League content such as Legion, Blight, Delirium, Heist, Ritual, Expedition and Delve now instead drop Stacked DecksStacked DeckStack Size: 20A stack of unknown divination cardsRight click to take a divination card out of the deck..
3.20.1	The Blight Atlas Passives that provided your Maps with Blight Encounters a chance to contain an additional Blight Encounter have irreconcilable issues that result in areas with two Blight Encounters failing to generate reliably, so we have replaced these stats.
3.20.0	We want to improve on the concept that the Atlas Tree allows players to invest into leagues that they enjoy, and have added new clusters to the passive tree for league content that can be blocked through Atlas Passive Skills. We've also increased the chances for such league content to appear.
3.17.0	It is now possible to have multiple Blight Encounters in a single Area through the new Blight Atlas Passive Skills.
3.14.3c	Fixed a bug where Blight chests were not displaying their reward type.
3.14.0c	Fixed a bug with Blight Encounters where Zombie Rhoas and Rattleback, Hollow Matriarch could become invulnerable.
3.14.0	Reduced the chance for Map Areas to contain Abyss, Ambush, Blight, Breach, Domination, Essence, Heist, Legion, Metamorph and Torment encounters by 20%. The chance to encounter a Zana mission containing any of these mechanics has also been lowered by the same amount. Spawn chance in map has changed to 8%^[3]
3.12.0	Arc Towers now cast 74% faster. Shock Nova Towers now cast 50% faster. Chilling Towers now have 50% more Chill effect, and have a cooldown of 4 seconds (from 7). Seismic Towers now have 50% more skill effect duration and have a cooldown of 4 seconds (from 7). Minion Towers now wait 3 seconds before resummoning their dead minions (from 8). Freezebolt Towers now cast twice as fast and have half their previous cooldown. They now fire an additional projectile. Stone Gaze Towers now reduce action speed by 20% (from 15%) and have slight reduced cooldown. Scouts from Scout Towers now have 38% more Attack Speed and deal 50% more damage.
3.8.0	Introduced to the game.

References

↑ https://youtu.be/s1GNBQsNRUQ?t=2582
↑ https://www.pathofexile.com/forum/view-thread/3324396#11/04-1
↑ Chris (April 9, 2021). "Path of Exile: Ultimatum Content Reveal". Path of Exile Youtube Channel. Retrieved April 9, 2021.

[1] ttps://youtu.be/s1GNBQsNRUQ?t=2582

[2] ttps://www.pathofexile.com/forum/view-thread/3324396#11/04-1

[3] Chris (April 9, 2021). "Path of Exile: Ultimatum Content Reveal". Path of Exile Youtube Channel. Retrieved April 9, 2021.

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