Inno, the attackspeed works like this.
Attackspeed is named Rate of Fire in the Lua files, and describes how many shots/hit per second you do. Example the Rook.
Rook has a RoF of 0.3, this means he needs 3.33sec. for a swing. Now, you go and buy the +50% attackspeed boots, his RoF will change to 0.45 (Calculated: 0.3+0.3*0.5 or to better adjust to modifiers 0.
(1+0.5)) => 2.22sec for a swing.
If you add now an additonal item with 20% attackspeed it'll look like: 0.
(1+0.5+0.2) => RoF: 0.51 => 1.96sec
So they stack: 20 + 50 = 70% , else it would be to insane.
IF you do it like u said it would be: Basespeed*1.5*1.2 = 0.54 => 1.85sec - nice diffrence, but to show you how hard it would be, lets stack additional 30% to it.
1. 0.
(1+0.5+0.2+0.3) = 0.6 = 1.6 sec. Means 50% + 20% + 30% = 100% more attack speed.
2. 0.3*1.5*1.2*1.3 = 0.702 = 1.42 sec. means 50%*20%*30% = 134% more attack speed.
Percentage dont get multiplied normaly.
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Additional info: if found somethin intressting
Primary = 'Power',
This is out of rooks file, it means, there are Attributes. I recognize, that if you check the Stat-Skill of regulus, there are also 3 Stats mentioned.
So long, Aspartem 