Types of Damage

 Physical damage.:

                Physical damage is dealt by all normal attacks from all the units in DotA, and also by few of the spells. Physical damage taken by a hero is reduced by armor and damage block and is unaffected by magic immunity and resistance. Ethereal units cannot be attacked by physical attacks.

There are a number of attack types that causes physical damage, depending on the source, which are reduced by different types of Armor.

Hero Attacks:

They do 100% damage against all the units in DotA except the fortified towers and siege creeps, which take only half damage (50%) from heroes.

Piercing Damage

They do 50% reduced damage against heroes but 150 %( bonus 50%) damage against Creeps. This type of damage is possessed my Venomancer’s plague ward which makes it more helpful to control the lane rather than to harass heroes also possessed by creeps.

Siege Damage

They do 150 %( bonus 50%) damage against fortified tower and siege creeps but 75% reduced damage against the heroes. This type damage type is possessed by siege creeps and towers.

Chaos Damage

They do 100% damage to all units in DotA but 40% of damage in opposition to the fortified towers and siege creeps. This type of damage is possessed by warlock’s infernal and also by ancient units as well as fountain of health.

Magical Damage:

It is caused mostly by casting spells, while not all the spells do magical damage. It is reduced by magic resistance and does 1.3-1.5 more damage to ethereal units but magic immune units are unaffected by this. Like Dragon knight’s Dragon breath.

Mixed Damage:

It is a combination of both the physical and magical damage types. These types of damage are reduced by magic resistance, amour and damage block but not by magic immunity and ethereal units are not affected by this type of damage. Like Leshrac's Diabolic Edict.

Pure Damage:

This type of damage ignores all armor, damage block and magic resistance as well. It does normal damage against ethereal units but doesn’t affect magic immunity units. Like Enchantress' Impetus.

HP Removal:

This type of damage ignores all damage reductions and affects units under magic immunity and invulnerability and does physical damage against ethereal units. Like Necrolyte's heart-stopper Aura.