Attack Speed

The speed at which units attack is measured in Attack Speed. A unit's attack speed can be increased by items, Agility, buffs from spells, auras and passive abilities. There's no limit for attack speed, but the fastest you can attack is 0.29s per attack (equals ~518 attack speed).

Base Attack Time (BAT)
Every unit has its own base attack time. It is the amount of seconds between each attack of a unit. This value cannot be changed (except by certain hero transformation abilities, such as Alchemist's Chemical Rage), but what can change is the unit's Increased Attack Speed.

All heroes have a BAT of 1.7 except for the following:


 * Anti-Mage: BAT 1.45
 * Windrunner: BAT 1.5
 * Huskar: BAT 1.6
 * Soul Keeper: BAT 1.5 (BAT 1.6 (under Metamorphosis)
 * Alchemist (under Chemical Rage): BAT 1.45/1.3/1.15
 * Lycanthrope (under Shapeshift: BAT 1.5
 * Troll Warlord (under Berserker Rage): BAT 1.55
 * Lone Druid (under True Form): BAT 1.6

Increased Attack Speed (IAS)
Increased attack speed works together with base attack time to determine how fast a unit can attack. IAS has a maximum limit of 400 and a minimum value of -80.

Attack Speed Formula
To determine how fast a unit attacks, the formula below is used:


 * Attacks per second = (1 + IAS)/BAT

Note: IAS in this formula is a percentage, so you must divide your actual IAS by 100 before using it in this formula.

List of items