User blog comment:The5lacker/Varus is not a normal AD carry/@comment-4452268-20130615004005

The special thing about AD Carries is, that they don't have to scale well with their abilities. They innately scale well simply because they are AD Carries. The high-end AD itemiziation is so freakishly good that it would be enough on it's own for any champion. The "problem" with it is its power curve and the high gold requirement, so ADCs rely on basedamage and ability scaling in the early- and midgame. Lategame however, Infinity Edge crits and Bloodthirster heals at a super fast rate outdamage everything DPS-wise (Not to be confused with AP Burst).

Which means: The qualities of an AD Carry are mostly:

Survivability / Mobility (See Ezreal, Vayne, Graves, Caitlyn)

Lane Dominance (Graves, Draven)

Poke (Ezreal, Corki, Kog'Maw, Caitlyn)

And to some degree, damage steroids. Tristana, Draven, Vayne and maybe Kog'Maw are propably the Carries with the heaviest steroids for lategame, and even those are not abilites that scale well with AD, but steriods that further improve the mechanics of the IE/PD/BT items.

Therefore saying that an AD Carry is not an AD Carry or shouldn't be played that way because he also scales well with AP or doesn't scale with AD good enough is wrong.