Talk:Katarina/@comment-24.87.155.243-20120724012910/@comment-4881935-20120724013500

Every champion starts with some base attack damage that increases each level.

Anything else is consider bonus attack damage. So, items, champion abilities, buffs, runes and masteries that grants attack damage for the champion are consider bonus attack damage.

so to answer your question, it only scales off of AD that you acquire outside from your base stats and levels.