Magic Armor
Magic Armor reduces the amount of damage you take from Magic Damage. Having a positive amount of Magic Armor will reduce Magic damage by a percentage, while negative Magic Armor amplifies it. Magic Armor is independent from Armor, and does not reduce Physical or True damage.
Formula
How magic armor damage reduction is calculated.
| Name | Formula |
|---|---|
| Damage Reduction (MA ≥ 0) | ((0.06 × MA) / (1 + 0.06 × MA)) × 100 |
| Damage Increase (MA < 0) | 1 − 0.94^−MA |
Base Magic Armor
All heroes have a base amount of Magic Armor, which does not change with levels. A majority of heroes have a base Magic Armor of 5.5, a 24.8% reduction. Prior to Version 2.6.24, all heroes had a Magic Armor of 5.5.
| Heroes | baseMagicArmor | damageReduction |
|---|---|---|
| All Other Heroes | 5.5 | 24.8% |
Sources
Magic Armor Modifier
Items that provide magic armor bonuses.
| Item | Magic resist | Notes |
|---|---|---|
| Mystic Vestments | +5 | |
| Null Stone | +5 | |
| Spell Sunder | +5 | |
| Shaman's Headdress | +4 | |
| Barrier Idol | +3 | |
| Helm of the Black Legion | +2 | |
| Ring of the Teacher | +1 |
Abilities
Abilities that provide magic armor bonuses.
| Unit | Source | Target | Magic resist | Duration | Notes |
|---|---|---|---|---|---|
| Demented Shaman | Restoration | Ally Units | +2/3/4/5 | 10 seconds | |
| Empath | Synergy | Ally Units (Aura) | +1/2/3/4 | N/A | |
| Keeper of the Forest | Nature's Guidance | Ally Unit | +1/2/3/4 | 15/30/45/60 seconds | |
| Pearl | Preservation | Ally Units | +2/3/4 | Up to 7/8.5/10 seconds | Applies to units inside the bubble |
Magic Armor Reduction
Abilities and items that reduce enemy magic armor.
| heroItem | Source | Target | reduction | Duration | Notes |
|---|---|---|---|---|---|
| Defiler | Unholy Expulsion | Enemy Units | 1/2/3/4 | Up to 4 seconds | Applies while tethered |
| Plague Rider | Earthblight | Enemy Units | 1/2/3/4 | Up to 4 seconds | Applies while tethered |
| Revenant | Mortification | Enemy Units | 1/2/3/4 | 6 seconds | |
| Void Talisman | Activation | Self | 5.5 | 4 seconds |
Magic Armor Penetration
Magic Armor Penetration causes Magic Damage to ignore a certain amount of Magic Armor. Unlike Magic Armor reduction, Magic Armor Penetration benefits only the user. Magic Armor Penetration will only ignore up to how much Magic Armor the target has, and has no effect if Magic Armor value is negative.
| unitItem | Source | Target | Penetration | Duration | Notes |
|---|---|---|---|---|---|
| Lodestone | Shatterstorm | Enemy Units & Self | 100% | 5 seconds | |
| Rhapsody | Arcane Hymn | Ally Heroes (Aura) | 0.5/1/1.5/2 | N/A | |
| Sir Benzington | Heart Piercer | Passive | 1/2/3/4 | N/A | Does not apply to items |
| Spellshards | Passive | Enemy Units | 60% | N/A |