[{quoted}](name=Ninja Baby one,realm=EUW,application-id=3ErqAdtq,discussion-id=YLfu79QV,comment-id=0000,timestamp=2016-09-06T13:34:53.147+0000)
Why though? Some champions make sense to have their passives level up and you know what? Their passive automatically levels up. But then there's other champions where it doesn't make sense to have their Passives level up. Like, how would you level up Zilean's passive? How would Corki's passive level? What about Draven? The way the game works right now is fine. Ontop of most games you don't even make it to level 18, the things can't be balanced proper.
Zilean generates 2 / 3.5 / 5 / 6 / 12 experience every 5 seconds
rank 1 Zilean generates 3 experience every 5 seconds
rank 2 Zilean generates 6 experience every 5 seconds
rank 3 Zilean generates 12 experience every 5 seconds
When Draven kills an enemy champion, he consumes all of his Adoration stacks and gains 50 + (2 × stacks) Gold. Draven loses half of his Adoration stacks upon death
Rank 1 gains 50 + (2 × stacks) Gold
Rank 2 gains 50 + (3 × stacks) Gold
Rank 3 gains 50 + (4 × stacks) Gold
Hextech Shrapnel Shells: Corki's basic attacks are permanently modified to deal 50% AD physical damage and 50% AD magic damage
Rank 1 50% AD physical damage and 50% AD magic damage
Rank 2 60% AD physical damage and 60% AD magic damage
Rank 3 70% AD physical damage and 70% AD magic damage
So as you see ain't that hard to figure out how the passive ranking would work
Its not necessary to reach level 20 at 100% of the played that are played even if you finish the game at level 15 but I can assure you that I am level 18 most of my games. I assume that you Surrender at 20 often :3