
“ | ▶️ Thy magic harms me not.
— Anti-Mage
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Magic Resistance is a stat that reduces (or increases, if negative) magical damage a unit takes from spells and magic attacks. Every unit is capable of gaining or losing magic resistance, and most units start with a small amount of base resistance. A hero's magic resistance can be passively increased with talents, certain items, and some abilities. Magic resistance of any unit can also be temporarily increased or reduced with some abilities.
Total magic resistance is defined as
Magic Resistance = 1 - (1 - Base Magic Resistance) × (1 - Magic Resistance Modifiers i )
Contents
Base Magic Resistance[]
Base Magic Resistance is a value that never changes throughout a game. It consists of one fixed value set for each unit individually. The base magic resistance of a unit can be a negative number.
Heroes
All 123 heroes currently have the same Base Magic Resistance value: 25%
Creeps[]
Units | Magic resistance |
---|---|
Mega Melee Creep, Mega Ranged Creep, Melee Creep, Ranged Creep, Super Melee Creep, Super Ranged Creep | 0% |
Lycan Lane Wolf | 70% |
Siege Creep, Super Siege Creep | 80% |
Summons[]
Summons | Magic resistance |
---|---|
Astral Spirit, Earth, Fire, Spirit Bear | 0% |
Void | 20% |
Storm | 25% |
Warlock Golem | 33% |
Familiar | 35% |
Base Magic Resistance Negation[]
Some abilities negate or ignores a unit's base magic resistance by removing a percentage of the base magic resistance on the target. This magic resistance negation only affects the base magic resistance value of units, other sources of magic resistance are not affected.
Natural Order (and Astral Spirit's Natural Order) interact with magic resistance differently. Instead of stacking multiplicatively with other sources of magic resistance, it acts as a multiplier for the base magic resistance. These two abilities are currently the only two sources of base magic resistance negation, and it is defined as
This means, for heroes with 25% base magic resistance, Natural Order reduces magic resistance by 10%/15%/20%/25%, down to 15%/10%/5%/0%.
- Radius: 350
Base Magic Resistance Reduction: 40%/60%/80%/100%
While Astral Spirit is not summoned, the spirit is hidden and periodically moved along with Elder Titan, so that effectively, it is centered around him. - Radius: 350
Base Magic Resistance Reduction: 40%/60%/80%/100%
The effects are provided by an aura, affects enemies within range of the Astral Spirit. The reduction is based on the enemies' base magic resistance. The debuff lingers for 1 second.
Pure Damage[]
Pure Damage is a damage type that is not reduced by Armor or Magic Resistance. It is also not amplified by magical damage amplification abilities, fully ignores Armor and Damage Block. It does not affect invulnerable units.
There are a few sources that can manipulate Pure Damage, with Dispersion being one of them. This mechanic is called damage reduction. Pure damage affects units with Spell Immunity (because spell immunity does not block damage), but that does not mean that an ability that deals pure damage is able to target spell immune units.
Total Magic Damage[]
Calculating the total magic damage of an ability involves using a few multipliers, Magic Resistance Multiplier, Actual Base Magic Resistance, Magic Damage Barrier and Magic Damage Negation Sources (if any). The total or actual magic damage dealt is equal to how much health a target immediately loses as a direct result.
Actual magic damage dealt after magic resistance is defined as
Magic Damage Dealt = (Magical Damage - Magic Damage Barrier - Magic Damage Negations) × (1 - Magic Resistance)
Magic Damage Barrier absorbs a set amount of magic damage before it is reduced by magic resistance.
Magic Resistance Stacking[]
Multiple sources of magic resistance stack multiplicatively. This means a unit's magic resistance value changes less the higher its magic resistance is, and more the lower it is. This prevents a unit from reaching 100% magic resistance by stacking different sources up. All sources of magic resistance modification stack fully with the exception of Ethereal buffs and debuffs.
Total magic resistance is defined as
Magic Resistance = 1 - (1 - Base Magic Resistance) × (1 - Magic Resistance Modifiers i )
However, there are a few abilities that directly sets a unit's magic resistance to 100%, e.g. Fate's Edict.
- Example 1
- Anti-Mage have Level 4 Counterspell and a Cloak. What is his current magic resistance?
- Base hero magic resistance: 0.25
- Bonus magic resistance: Counterspell: 0.45, Cloak: 0.15
- Magic resistance reduction: 0 (None)
- Total Magic Resistance
- = 1 - ((1 - 0.25) × (1 - 0.45) × (1 - 0.15))
- = 64.94%
- Anti-Mage's current magic resistance in this example is 64.94%.
- Example 2
- Visage is at max level under the effect of a Level 4 Ancient Seal and a Level 4 Decrepify. What is his current magic resistance?
- Base hero magic resistance: 0.25
- Bonus magic resistance: 0 (None)
- Magic resistance reduction: Ancient Seal: -0.35, Decrepify: -0.6
- Total Magic Resistance
- = 1 - ((1 - 0.25) × (1 + 0.35) × (1 + 0.6))
- = -62%
- Visage's current magic resistance in this example is -62%. Magic resistance reduction's calculation is highlighted red in this example.
Magical Damage Barrier[]
Magical damage barriers absorb a flat amount of magical damage, no matter whether it comes from abilities (magical spell damage) or attacks (magical attack damage). The barrier absorbs the damage before it is reduced by magic resistance, and it is defined as the formula above.
- Example
- Anti-Mage has a 300 health damage barrier, and gets hit by 400 magical damage. How much actual magical damage will he take?
- Base magic resistance: 0.25
- Magical Damage Taken
- = (400 - 300) × (1 - 0.25)
- = 75
- Anti-Mage will take 75 magical damage in this example.
This means the exceeding 100 magical damage is not absorbed and the damage is reduced by Anti-Mage's base 25% magic resistance to 75 magical damage. In this example, Anti-Mage takes 75 magic damage. This means a barrier is more effective the lower a unit's magic resistance is, similar to how damage block is more effective, the lower the armor is.
Magical Damage Barrier Stacking[]
Multiple sources of magical damage barriers work independently and do not stack. When a unit is affected by multiple magical damage barriers, all of them deplete at the same time.
However, if a unit is affected by multiple barriers receive a damage instance that is greater than all barriers individually, the damage gets blocked as if the barriers were one barrier with combined capacity.
Magical Damage Barrier stacking is defined as
Magical Damage Barrier =
With x
being the incoming magical damage value, B
the source(s) of the magical damage barrier value.
- Example 1
- Ember Spirit is affected by Level 4 Flame Guard and Barrier of Pipe of Insight. He then takes 250 magical damage. Both magical damage barriers will lose 250 capacity.
- Barrier capacity: Flame Guard: 400, Barrier: 400
- Since the incoming magical damage is less than B1 and B2:
- B1 ( Flame Guard)
- = 400 - 250
- = 150
- B2 ( Barrier)
- = 400 - 250
- = 150
- Since incoming magical damage is less than all individual barriers. Both Flame Guard and Barrier will now have 150 and 150 remaining magic barrier capacity respectively in this example.
- Example 2
- Ember Spirit is affected by Level 4 Flame Guard and Barrier of Pipe of Insight. He then takes 1000 magical damage.
- Barrier capacity: Flame Guard: 400, Barrier: 400
- Since the incoming magical damage is more than B1 and B2 combined:
- Incoming Magical Damage
- = 1000 - (400 + 400)
- = 200
- Since incoming magical damage is greater than the sum of both barriers, both Flame Guard and Barrier are depleted, and magical damage is blocked as if the barriers were one barrier with combined capacity, highlighted in blue in this example. Ember Spirit takes the remaining 200 damage before applying magic resistance.
Magical Damage Barrier Sources[]
Effective HP[]
The total amount of magic damage a unit can take due to magic resistance is known as effective HP (or EHP). Despite each source of magic resistance increasing the magic resistance value less the higher it is and making them seem less effective, each sources increases the unit's effective HP against magic damage by their base value.
A unit with 0% magic resistance has 100% effective HP against magical damage, means magical damage equaling 100% of its health is required to kill it. All 123 have 25% magic resistance by default, making their effective HP against magical damage 133.33%.
Magic Resistance | -100% | -75% | -50% | -25% | 0% | 25% | 50% | 75% | 100% |
---|---|---|---|---|---|---|---|---|---|
Effective HP | 500 | 571 | 667 | 800 | 1000 | 1333 | 2000 | 4000 | ∞ |
This definition of EHP assumes all damage taken is magic damage. EHP against physical damage (such as basic hero attacks etc.) is modified by armor.
Effective HP against magical damage is defined as
EHP = Σ CurrentHP / (1 - Σ Magic Resistance)
Instead of diminishing in effectiveness, multiple sources of resistance are actually more effective stacked than they are individually. Two sources of 25% resistance stacked provides 77.78%, extra EHP whereas one source provides 33.33%.
Examples[]
- Example 1
- Anti-Mage at max level has 1540 health with Level 4 Counterspell and a Cloak, how much EHP against magical damage he has?
- According to the previous example in magic resistance stacking above, Anti-Mage with Level 4 Counterspell and a Cloak has a magic resistance of 64.94% (or 0.6494).
- Base magic resistance: 0.25
- Bonus magic resistance: Counterspell: 0.45, Cloak: 0.15
- EHPm
- = 1540 / (1 - 0.649375)
- = 4392.16
- Anti-Mage has 4392.16 EHP against magical damage in this example.
- Example 2
- Visage has 2260 health at max level. While under the effect of a Level 4 Ancient Seal and Level 4 Decrepify, how much EHP against magical damage he has?
- According to the previous example in magic resistance stacking above, Visage who is affected by those two abilities will have a magic resistance of -62% (or -0.62).
- Base hero magic resistance: 0.25
- Bonus magic resistance: 0 (None)
- Magic resistance reduction: Ancient Seal: 0.35, Decrepify: 0.6
- EHPm
- = 2260 / (1 - (-0.62))
- = 1395.06
- Visage has 1395.06 EHP against magical damage in this example.
Modifying Magic Resistance[]
Several abilities and items have abilities that grant or reduce magic resistance.
Magic Resistance Increasing Sources[]
Anti-Mage – Counterspell
Arc Warden – Magnetic Field2b
Brewmaster – Drunken Brawler Earth Stance
Centaur Courser – Cloak Aura
Dragon Knight – Black Dragon Form2a
Glimmer Cape – Glimmer
Huskar – Berserker's Blood
Lone Druid – Demolish
Oracle – Fate's Edict
Spirit Bear – Demolish
Meepo – Divided We Stand
Pipe of Insight – Insight Aura
Pudge – Flesh Heap
Vambrace – Switch Attribute
Viper – Corrosive Skin
- 1 Requires
talent.
- 2a Requires Aghanim's Scepter.
- 2b Requires Aghanim's Shard.
Talents[]
The following heroes have a talent that grants them bonus magic resistance.
Bonus | Level 10 | Level 15 | Level 20 | Level 25 | ||||
---|---|---|---|---|---|---|---|---|
Left | Right | Left | Right | Left | Right | Left | Right | |
Magic Resistance |
With the 25% magic resistance and no other sources of magic resistance, the following heroes with bonus magic resistance talents effectively have their magic resistance increased up to:
Heroes | Magic Resistance Talent | Magic Resistance Total | Increased Value |
---|---|---|---|
Basic Magic Resistance (25%) | |||
![]() |
+10% | 32.5% | +7.5% |
![]() ![]() ![]() ![]() ![]() |
+12% | 34% | +9% |
![]() ![]() ![]() |
+15% | 36.25% | +11.25% |
Besides these, the following heroes have talents which increase the magic resistance of the units they summon
Items[]
These items grant bonus magic resistance to the hero who has them equipped.
Item | Value | Item Cost | Cost/Value Point |
---|---|---|---|
Arcanist's Armor | 20 | N/A | N/A |
Bloodthorn | 20 | 6800 ![]() |
340 ![]() |
Cloak | 15 | 500 ![]() |
33.33 ![]() |
Cloak of Flames | 10 | N/A | N/A |
Eternal Shroud | 20 | 3300 ![]() |
165 ![]() |
Glimmer Cape | 15 | 1950 ![]() |
130 ![]() |
Hood of Defiance | 18 | 1500 ![]() |
83.33 ![]() |
Mage Slayer | 20 | 2400 ![]() |
120 ![]() |
Nether Shawl | 20 | N/A | N/A |
Pipe of Insight | 30 | 3475 ![]() |
115.83 ![]() |
Titan Sliver | 16 | N/A | N/A |
Trickster Cloak | 20 | N/A | N/A |
Vambrace (Strength) | 10 | N/A | N/A |
Values may include portions from actives or auras. |
Magic Resistance Reducing Sources[]
- 1 Requires
talent.
- 2a Requires Aghanim's Scepter.
- 2b Requires Aghanim's Shard.
Ethereal[]
Ethereal, sometimes referred to as ghost form, is a type of status effect that makes affected units immune to all physical damage, grants them attack immunity, while also disarming them. It also reduces their magic resistance, causing them to take additional magical damage. Affected units are able to control every other aspect of their character.
The magic resistance reduction of multiple ethereal effects does not stack, the one with higher value takes priority, and it is defined as
Eth = (1 - MAX Ethereal Magic Resistance Reduction)
Spell Immunity[]

Spell immunity (formerly known as magic immunity) is a modifier which prevents most spells to target the affected unit. This includes single-targeted, area of effect, passive and active abilities. A unit having 100% magic resistance does not equal to being spell immune. Therefore, Spell Immunity and Magic Resistance are separate and different mechanics.
Version History[]
- Fixed magic damage sources from attacks not being blocked by magic damage barrier type abilities (i.e. Barrier, Flame Guard etc.).
Patch History[]
- Fixed recasting magic damage barrier abilities not resetting the damage capacity of the magic barrier.
- Update 2
- Fixed magical damage amplification when a unit drops below 0% magic resistance.
- Fixed magic resistance not stacking properly.
- Fixed various magic resistance rules.
- Fixed bugs with how magic resistance from base and items were calculated on illusions.
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