Weapon Speed is an item stat determining how quickly a weapon is to use between swings/fired shots.
The calculation is currently unknown for Diablo 4.
Below are very basic explanations on how it Weapon Speed/Attack speed was calculated in previous games.
How it worked in Diablo 3
Weapon Attack Speed in Diablo 3 depends on the weapon type and works differently from previous Diablo games. It ranges between 1.20 to 1.60 APS for one-handed weapons and 0.90 to 1.15 APS for two-handed weapons.
In Diablo 3 there are what could be considered two types of attack speed. The first is the modified weapon speed increased by affixes. The second is the sum of all other increased attack speed factors. These modifiers are multiplied to give an overall attack speed.
How it Worked in Diablo 2
Diablo 2 weapon speed is calculated in increments of 10 and is relative compared to other weapons.
- -20 [Faster]
- Base: -
- 20 [Slower]
Each 10 is equivalent to an SIAS item (Skill Increased Attack Speed).