Talk:Gangplank/@comment-25333612-20150828015558/@comment-5931083-20150828193417

It goes in this order: Flat armor reduction, then percentage armor reduction, then percentage armor penetration, flat armor penetration being the last one to apply. Bear in mind you cannot get anyone below 0 armor using penetration.

It is only possible to get a target below zero by using flat reduction which is scarce now (Corki, Nasus, Rammus and Taric still wield some, the rest was remade to percentage). Their powers combined can shave roughly 150 armor off an enemy, but other than Nasus(E), they all require either close range or time to get stacked.

Wow, before reading it on Wiki, I didn't know how great synergy can Nasus have with other AD champs. Combined with some flat penetration of his ally, it could well get a squishy enemy to zero armor, turning attacks into true damage.