How Does Attack Speed Works?

[saint]

How attack speed works?
Introduction to base terms:

BAT is Base Attack Time
IAS is Increased Attack Speed
DPS is Damage per Second

100 agility = 1 IAS
100% IAS = 1 IAS

( 1 + IAS ) / BAT = attacks per second

How do I know that BAT of my hero?

BAT is 1.7 for all heroes except:

Vengeful Spirit (Shandelzare Silkwood) - Attack Cooldown: 1.77
Soul Keeper (Terrorblade) - Attack Cooldown: 1.5
Soul Keeper (Terrorblade ;morphed) - Attack Cooldown: 1.6
Troll Warlord (Ranged) - Attack Cooldown: 1.8
Troll Warlord (Melee) - Attack Cooldown: 1.6
Lone Druid (True Form) - Attack Cooldown: 1.6
Anti-Mage (Magina) - Attack Cooldown: 1.45
Lycanthropy (Banehallow ;Morphed) - Attack Cooldown: 1.4


How does my hero benefit from IAS?

Increased attack speed stacks, but the stacking is additive. Also, each point of agility gives +1% IAS. So a hero with 40 agility (+40% IAS), a hyperstone (+55% IAS), and power treads (+30% IAS) has a total of 125% IAS.


Are there upper and lower limits for attack speed?

Yes. Upper limit is 500% of your original speed, lower limit is 20%.


OK so how exactly do I work out the attack speed?

A hero's IAS is computed by adding the hero's agility with the sum of any IAS items.

So your level 1 Troll (with 21 agility) with hyperstone would have

base attack speed == 1/1.7 == .5882352941 hits/sec
IAS == 21% (agility) + 55% (hyperstone) == 76% == 0.76

So current attack speed == (1/1.7 * (1 + 0.76)) == 1.035 hits/sec

Current DPS, if the Troll has 50 damage, will be 50*1.035= 51.75 DPS <--- this number is what matters the most.

Credits to lh2128.