by Greg on Mar 31, 2015
For a lot of games damage is damage. The amount of damage your character has directly equates to the amount of health removed from an enemy after hitting them. While this is true in Dota 2 in some circumstances, there are six different forms of damage to consider. Physical, Magical, Pure, Universal, Composite, and HP removal all have their own properties to consider, and react differently to defences like armor or magic resistance. Knowing what type of damage your hero can produce and what items enhance what type of damage done is essential in maximizing the effectiveness of your build against the enemy teams defences.
Physical Damage is the most common form of damage in Dota 2 and is done by everything from creeps to towers, to heroes. All regular attacks by all of the units in the game cause physical damage. In addition to that, some abilities will cause physical damage as well. Physical damage can be mitigated by armor and damage block. Ethereal units are not affected by physical damage. Physical damage can also be broken down further into five sub categories.
Piercing - Dealt by ranged creeps, it only deals 50% damage to heroes and buildings but 150% against other forms of creeps. Siege Damage - Dealt only by towers and siege creeps. Does 150% damage to other towers and siege creeps, but only 75% to heroes. Chaos Damage - Dealt mainly by neutral creeps and hero summons. Deals 100% damage to everything except buildings and siege creeps to which it only does 40% damage. Hero Damage - Hero physical damage is 100% effective to all units except for buildings and siege creeps to which they are only 50% effective. Hero damage is mitigated by armor. Normal Damage - Dealt be melee creeps and some hero summons. Deals 75% damage to heroes and 70% damage to buildings.Pure damage is a type of magic damage that cannot by mitigated by magic resistance or blocked by damage block. It will always deal 100% of it's damage to the enemy hero and can only be stopped by magic immunity. In additional to not being mitigated by magic resistance, it cannot be amplified by items either. An example of pure damage is Pudges "Meat Hook".
Composite damage (also known as mixed damage) is a lot like physical damage only that it can also be mitigated by magic resist. It does not effect ethereal units but it can deal damage to units with magic immunity. An example of composite damage is the Alchemists "Acid Spray" ability.
Magic damage is the second most common form of damage dealt. Almost all spells cause magic damage, and it is one of the only forms of damage to hurt ethereals. Magic damage is mitigated by magic resistance, much like physical damage is by armor. Magic damage can also be blocked completely by magic immunity. Every hero in Dota 2 starts with 25% magic resistance, meaning the damage a spell says it does will be at least 25% lower, and more if the enemy bought items with additional magic resistance. An example of Magic damage would be Spirit Breaker's "Nether Strike".
Universal damage is exactly like magic damage only it has the added benefit of being able to pierce units with magic immunity. It is however mitigated by magic resistance. An example of a Universal ability is Doom's "Doom" spell.
Much like pure damage, HP removal damage is not mitigated at all by armor or magic resist. In addition to that, HP Removal can not be stopped by magic resistance or any other type of immunity. HP removal is also unique because it is not really considered an attack and thus can't be killed by an HP removal spell. An example of HP Removal is Vengeful Spirit's "Wave of Terror".