DotA Heroes' Attack Speed

Attack speed
The max attack speed for a hero is 400%, any higher is wasting your gold. However I recommend that your attack speed be at 200% when you reach level 25 and with more damage items than speed. As anything higher than 200% the increase in overall AS is not worth the gold and the DPS output is far lower if you went for damage.

On calculating your AS, you have to take into account the AS given by agi items and the hero's own AS increase per level. This is crucial that you know if the hero will gain high Agi and Attack speed per level so that you can put more money into Damage items than AS items. A rough idea where 200% increase in AS is by looking at Juggernut's onmislash with Batterfury on. you will see him doing a cleave attack every hit of the onmislash if you have reached 200%. A easier way is to go to Dota-Allstars.com and use their hero builder to check if your hero with the full set of items is at 200% attack speed.

This is crucial is if you are working to be a DPS hero, while other heroes will also benift from the increase in damage output