Ancient (Building)

This article is about the two Ancients on either side of the map, and the main objective of the game. For other uses, see Ancient (disambiguation).
Main Article: Ancients (Buildings)
## Abilities

Backdoor Protection ▶️

**Ability**
Passive / Aura
**Affects**
Self

Structure takes reduced damage, and quickly regenerates any damage taken while no enemy creeps are nearby.

**Tier 2 Tower Search Radius:** 900**Ancient Search Radius:** 4000**Heal per Second:** 180**Damage Reduction:**  50%**Protected Illusion Damage Reduction:**  75%**Reactivation Delay:** 15**Aura Linger Duration:** 0.5Modifiers []

NOTES

* Each Backdoor Protection search radius functions independently of the other.
	+ The Ancient has a 4000 search radius, granting Backdoor Protection to all buildings inside the base, excluding the Fountain.
	+ Since the buildings within the base are based on the Ancient's search radius, they lose Backdoor Protection at the same time as the Ancient.

* The unit detection is aura-based. If an enemy lane creep enters the search radius, the Backdoor Protection for that building is automatically disabled.
	+ The aura's effect lingers for 0.5 seconds, so the total reactivation delay is effectively 15.5 seconds.

* Grants the following effects to the protected building while active:
	+ Self-heals 18 health in 0.1 second intervals upon any damage instance.
	+ Only heals from enemy damage sources, ally damage dealt (e.g. from denying) is not healed. It is possible to destroy protected buildings by dealing more than 270 damage per second (before reductions).
	+ Applies generic incoming damage reduction on the building. Affects all damage types the building takes that is not flagged as HP removal.
		- Stacks additively with other sources of generic incoming damage manipulation.
	+ Applies a unique incoming damage reduction with the incoming damage reduction of  Reinforced.
		- Stacks multiplicatively with other sources of unique incoming damage manipulation. Therefore, it further reduces the incoming damage from the following units while Backdoor Protection is active:
		- EXPR
			* Against illusions attack damage: `IllusionDamageDealt × 0.1`
			* Against illusions spell damage: `SpellDamageDealt × 0.25`
			* Against summons and Dominated creeps: `AttackDamageDealt × 0.225`

True Sight

**Ability**
Aura
**Affects**
Enemies

Adds the ability to see invisible units and wards to any allied vision within the structure's range.

**Radius:** 900**Aura Linger Duration:** 0.5Modifiers []

NOTES

* Grants unobstructed True Sight within 900 radius regardless of the building's actual vision.
	+ All effects are granted by an aura and its debuff lingers for 0.5 seconds.

* Fully affect invulnerable units.

* Cannot detect units under the following ability effects:
	+ Shadow Dance and  Depth Shroud.
	+ Disguise and  Solitary Disguise.

Reinforced

**Ability**
Passive

Reinforced Units and Buildings Deal Bonus Damage to other Reinforced Units and Buildings and take less attack damage from other units.

**Attack Damage Bonus Against Reinforced Units:** 50%**Hero Attack Damage Reduction:**  50%**Non-Hero Attack Damage Reduction:**  30%**Piercing Attack Damage Reduction:**  65%**Player-Controlled Units Attack Damage Reduction:**  10%**Illusions Attack Damage Reduction:**  60%Modifiers []

NOTES

* Treats creep-heroes and  Roshan as creeps.

* Reinforced units include all units with the  Reinforced ability (i.e.  Siege Creep and all buildings).

* If a non-hero unit has a piercing attack, it is only affected by the attack damage reduction against piercing attacks, and not by the reduction against non-hero units.

* Player-controlled units includes summons and Dominated creeps.
	+ Treat creep-heroes and illusions as heroes.