Warwick's strength lies in his durability and progressive lane domination thanks to his Q. This build is centered around maximising the utility of his Q, Madred's on-hit and his ult, which are all magic damage. Hence the focus on flat and percent magic penetration as well as magic resistance reduction from Abyssal Scepter.

Warwick is much like Irelia in that he has a lot of map presence and should be built tanky both before and after his core offensive items are completed (Madred's and Void Staff). With this build you should have somewhere around 200 armour and magic resistance.

Increases health pool to support your high armour and magic resistance, while giving your Q a strong slow during chase.