Originally Posted by Decendt
Identical auras on different champions stack. for example...if Ashe and a Heimerdinger has aaq Abyssmal scepter each. then a nearby foe will lose 40 magic resist...due to -20 from Ashe's, and -20 from Heimerdinger.
PS: Why would an Ashe have an Abyssmal Scepter...I do not know.
That is false.
The Aura's only stack on allied champions IF they also have the same item. So if Sivir and Shaco both have Stark's and are next to each other they will get a second copy of the 20% lifesteal and 20% attack speed buff but the -20 Armor will only apply once to nearby enemies however.
Then if the rest of their team joins them (Morgana, Pantheon, and Alistar) with Pantheon also having a Starks then Pantheon, Sivir, and Shaco would all have 2 copies of the buff, while Alistar and Morgana have 1. Enemies still only have one copy of the debuff.