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.

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.

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

 * Gloves of Haste +15 Attack Speed
 * Quarterstaff +10 Attack Speed
 * Force Staff +10 Attack Speed
 * Hand of Midas +30 Attack Speed
 * Power Treads +25 Attack Speed
 * Butterfly +30 Attack Speed
 * Armlet +15 Attack Speed
 * Orchid Malevolence +30 Attack Speed
 * Maelstrom +25 Attack Speed
 * Mjollnir +80 Attack Speed
 * Hyperstone +55 Attack Speed
 * Assault Cuirass +35 Attack Speed(+55 if we consider the aura it gives)