Illusions



Illusions (also commonly called illus) are imperfect, weaker copies of heroes, created by spells or items. They look like and are mostly treated like a hero, but are impaired, as they usually have incoming and outgoing damage penalties, dealing less damage and taking more damage than heroes. They are mostly incapable of casting spells or using active item abilities and also have some passive abilities disabled. They also may not drop or pick up items or runes. On the other side, illusions do not yield any gold or experience to the enemy when killed, and also do not soak up any AoE experience and gold (they cannot level up, and the gold from last hits they make goes to their owners) and do not interfere with kill streaks or counters.

Illusions can be created off of allied, enemy and the own hero, copying its appearance, level, attributes, attack values, defensive values like armor and magic resistance and their abilities on their current level. All items owned by the hero are copied as well, including all their stats (although some effects of abilities and items are disabled for illusions).

All illusions deal 25% less damage against buildings, making them weaker in pushing. This reduction stacks multiplicatively with the outgoing damage reduction which most illusions have, and also multiplicatively with the damage reduction hero damage does against structure armor type. However, due to the fact that illusions are based on heroes, their damage scales together with the heroes, making them still a significant pushing tool, especially in later phases of a match.

Visual appearance
All illusions have an extra texture layer, which makes them distinguishable from the original hero. There are 5 different type of textures which can be seen below.

To allies, illusions always appear with the texture layer, making them always look different than the original hero. For enemies, illusions which use the blue or the yellow textures appear like the original hero, making it difficult to tell them apart from the real hero. Illusions with the second or third texture appear like illusions to the enemy, means enemies do see their illusion textures. However, despite this, the portrait of illusions always appears like the original hero to the enemy.

Besides their skin and portrait, their health bar also differs based on whether the illusion is allied or not. Allied illusions have the same health bar as creeps. This also means their mana bar is not visible, as it is only visible when having a hero or creep-hero health bar. Besides this, illusions also have a circle on the left side of the health bar, which indicates their duration.

Enemy illusions use a hero health bar, to make it not obvious that they are illusions. They also display the player's name above them like regular enemy heroes (if the player has the name display turned on). The player name is based on the owner of the illusion, not of the hero the illusion is based on. This means when an enemy Shadow Demon creates illusion of allies, the illusions carry Shadow Demon's player name. The only exception to this is Morphling's Replicate, which displays the targeted allied hero's name, unless he targets an enemy, in which case it displays Morphling's player name.

Illusion creating abilities
These are all abilities which create illusions of heroes.

Stats
All 3 attributes of illusions (strength, agility and intelligence) are based on the original hero. They copy their base attributes, the attributes gained from levels, and all item bonuses. They fully benefit from every trait of attributes, health, health regen, mana, mana regen, armor, attack speed and attack damage. They also copy the hero's movement speed, base attack damage, attack animation (and projectile speed), base attack time, attack range, magic resistance, base armor, base health and mana regen, vision, collision size and turn rate. An illusion's stats, level, ability levels and items are all set upon spawn and do not adapt to the original hero.

Besides copying all the base stats of heroes, these bonus stats (from items or passive abilities) are also copied:
 * Attributes
 * Movement speed
 * Attack range
 * Health and mana
 * Vision
 * Base attack time

These bonus stats are not copied and thus do not work for illusions (although some of them are displayed in the HUD still):
 * Attack damage
 * Armor
 * Health regeneration
 * Mana regeneration

And finally, these bonus stats are very inconsistent, some sources work, some do not:
 * Attack speed
 * Magic resistance

Attack speed
Attack speed bonuses and reductions are inconsistent with illusions. Many of them do not affect illusions (although the HUD still displays them), but some do affect them, besides attack speed gained through agility.

Besides the attack speed bonuses of, and , direct attack speed bonuses from items do not affect illusions.

The base attack time changes from all sources (,, and ) fully affect illusions.

These abilities do increase or reduce the attack speed of illusions

1 Attack speed reductions.

These abilities do not increase or reduce the attack speed of illusions

1 Neither the attack speed bonus, nor attack speed slow of these spells affect illusions.

2 Attack speed reductions.

Magic resistance
Like attack speed, magic resistance bonuses are inconsistant with illusions. They either do, or do not affect them. If they do not, then the HUD does not display them either.

Magic resistance reducing effects fully effect illusions. Only increasing effects are inconsistant.

The 100% magic resistance granted by any source of spell immunity fully works for illusions.

These abilities do increase the magic resistance of illusions

These abilities do not increase the magic resistance of illusions

Copying buffs or debuffs
Usually when an illusion spawns, it does not copy the buffs and debuffs the original hero has. There are some exceptions though. However, they do copy toggle statuses of items and of some abilities.

The following buffs and debuffs are copied by illusions:

1 Although an infused Scepter's buff is copied, the attributes, health and mana bonuses are not. Only the upgrade effects are applied.

2 The Armlet buff gets copied and applies all its effects, except for the health loss.

3 The wolf form is copied, but the aura is not, so once Lycan returns to his default form, the Shapeshifted illusions no longer move at max speed and no longer crit.

4 Only the buff on Slark is copied by illusions. The debuff on heroes who lost attributes is not copied.

Most illusions cannot use active abilities and items. The only exceptions are Hybrid illusions, which are allowed to cast basic abilities, but not ultimates or Aghanim's Scepter-granted abilities and Vengeance illusions, which are allowed to cast regular and ultimate abilities, but not Scepter-granted abilities. Passive abilities work for all illusions, although many of them are disabled for them, and some have altered effects.

Attack modifiers
These attack modifiers fully work for illusions

1 Quell is the only attack damage bonus which fully works for illusions. The reductions of Split Shot and Marksmanship are the only reductions which affect illusions.

2 All 3 modifiers of Elder Dragon Form work for illusions, however, the poison debuff placed by illusions deals no damage.

These attack modifiers do not work for illusions

1 Places buff on the illusions on each attack, but does not apply the debuff on attack targets.

2 The particle effects of these attack modifiers appear and their sounds play, but their effects are not applied.

3 Tidebringer is always on autocast for illusions, so they proc whenever off cooldown, but non of its effects are applied.

Passive abilities
These passive abilities fully work for illusions

1 Each illusion has its own Greevil's Greed stack counter, working independent from the original.

2 Warpath does proc when illusions cast spells. Also, since Warpath always applies a stack on all owned illusions by default, illusions casting spells get 2 stacks per cast.

3 Unlike other direct armor bonuses, the armor bonus of Dragon Blood fully works for illusions.

These passive abilities do not work for illusions

1 The passive components of these active abilities do not work for illusions.

Auras
These auras are bestowed by illusions

1 Copies the toggle status of Radiance, Ring of Aquila and Ring of Basilius. They cannot be toggled on the illusions.

2 Vampiric Aura is always toggled off on illusions.

These auras are not bestowed by illusions

Active abilities
Almost all active abilities work normally for illusions. Only very few have a different effect when the caster is an illusion.

Ability interactions
Most abilities treat illusions like regular heroes. However, some abilities have a different effect or interact in a different way with illusions. A few abilities do not affect illusions at all.

These abilities instantly destroy illusions when used on or against them

1 Kills illusions on the first tick, not upon cast.

2 Illusions are destroyed, instead of getting petrified.

These abilities treat illusions as creeps, instead of heroes

These abilities do not affect, cannot target, or do not work against illusions

1 These abilities ignore the death of illusions, so killing them does not make these abilities apply their effects.

2 These abilities cannot target, or do not place their buffs or debuffs on illusions.

3 These lifesteal abilities do not work against illusions.

4 These abilities do not react on the presence of illusions or on damage or taken done by them.

Finally, these abilities have different interactions with illusions. They either do not treat them as heroes, or apply different effects on them.