Spell Immunity



Spell immunity (formerly known as magic immunity) is a status which prevents most spells from targeting the affected unit. This includes single-targeted, area of effect, passive and active abilities.

Spell immunity is not provided by any ability, but appears on some units as an extra layer of protection, usually on ward-type units, or in combination with invulnerability.

Spell immunity always comes combined with debuff immunity, which nullifies the effects of already existing debuffs on the unit.

Mechanics
Spell immunity is a status effect (also known as modifier). Most abilities in the game first check whether or not the unit is spell immune. If true, single-target abilities cannot target the unit at all, while area of effect abilities ignore the unit and already ongoing effects may stop affecting it. However, some abilities (and most ultimates) pierce spell immunity and can fully target and affect spell immune units.

Usually, a spell either fully pierces spell immunity, or it is fully blocked. However, there are a few exceptions to this rule. Whether or not a spell pierces spell immunity can be viewed in the interactions list.

When a unit turns spell immune while a projectile from an ability is already flying towards it, the projectile has no effect upon impact if the spell it originates from does not pierce spell immunity. The same applies to most, but not all delayed effects.

Spell immunity does not prevent regular attacks of any units. However, some attack modifiers do get blocked, but not all of them. Generally, critical strike, cleave, lifesteal, and most bashes pierce spell immunity.

Dispel
Certain modifiers periodically check for spell immunity and remove themselves if it is detected. The following abilities periodically check for spell immunity:

Debuff Immunity
Debuff immunity is an innate component of spell immunity, stopping the effects of already existing debuffs on the unit, allowing them to resume once the spell immunity and thus the debuff immunity expires.

Non-hero Units
Imunidade a magias Невосприимчивость к магии 技能免疫