Attack Speed

Main article: https://dota2.gamepedia.com/Attack_speed

Base Attack Time
All chess pieces have their own Base Attack Time (BAT). BAT is the time interval between attacks.

Base Attack Speed
All units have a base of 100 attack speed, The attack speed value 100 is expressed in percent, each attack speed point means 1% attack speed. But DotA HUD always normalizes attack speed relatively to 1.7s BAT. DotA calculates how faster unit attacks in percent if it has 1.7s BAT. For example, Bounty Hunter has 1s BAT. He attacks 70% faster than unit with 1.7s BAT therefore he has 170 Attack Speed in DotA HUD. You can easily compare attack time between different units using this normalized value.

Base Attack Speed as displayed on HUD can be calculated by formula:

1.7 / (Unit Base Attack Time) * 100

Attack Speed Bonus
Attack speed of chess piece can be changed by attack speed buffs, items or attack speed debuffs. Attack time (time interval between each attack) is calculated from the reciprocal of attack speed.

Attack time = Base Attack Time * 100 / (100 + Attack Speed Bonus)

For example, Bounty Hunter (1s BAT) with Quarterstaff (+10 Attack Speed) attacks on 10% faster therefore he attacks every 0.91s.

The cap to attack speed is 20 and 700, which can be reached with a bonus attack speed of -80 and +600 since each unit has 100 base attack speed.


 * At 20 attack speed, unit attacks 5 times slower.
 * At 700 attack speed, unit attacks 7 times faster.

Since DotA HUD normalized attack speed to 1.7s BAT it brings inconsistency to attack speed value. For example, the above Bounty Hunter has 110 attack speed without normalization but HUD says he had 189 Attack Speed.

Overall normalized Attack Speed of unit can be calculated by formula:

 1.7 / (Unit Base Attack Time) * (100 + Attack Speed Bonus) 

The following table shows normalized attack speed of items / auras / passive.