ad or armor pen runes

[quote=bluepower9]So i'm going to make a rune page with life steal quints and was wondering if i should get armor pen or ad reds. I already have armor pen and am using ad quints but for my new rune page i'm wondering if ad reds would be better because i'm going to have either 2 or 3 life steal quints and maybe 1 ad quint. BTW I main vayne if that helps at all.[/quote]

[quote=Luther3000]I'd go with AD on everything except Draven.[/quote]

[quote=A Chubby Baby]I'd say AD reds.[/quote]

[quote=Arcana3]Ad Reds...[/quote]

[quote=bluepower9]don't ad reds do overall less dmg cuz the armor pens are 1.28/ea but ad are .9x/ea[/quote]

[quote=Luther3000]Ehhh armour doesn't really work like that. They do roughly the same damage to champions (depending on how far into the game you are) but the important part is that AD also increases damage to minions and makes it easier to last hit whereas ArP does not.[/quote]

[quote=bluepower9][quote=Luther3000] Ehhh armour doesn't really work like that. They do roughly the same damage to champions (varies depending on level) but the important part is that AD also increases damage to minions and makes it easier to last hit whereas ArP does not. [/quote] ok but then how does armor work? doesn't armor pen make ur attacks do that much more dmg to the target? or how does it work?[/quote]

[quote=PsiGuard]http://leagueoflegends.wikia.com/wiki/Armor_penetration Use flat AD marks on ADCs, especially if you're running lifesteal. It'll help you push and sustain faster off minions, as well as simplifying last-hitting under turret. It doesn't really hurt your champion damage either.[/quote]

[quote=Luther3000]It's kinda complicated, but ArP works by ignoring that amount of your opponent's armour, and armour is a % reduction of incoming damage. It does increase your damage but the amount varies with your opponent and you can't just directly compare it with an equal amount of AD.[/quote]

[quote=bluepower9]thanks everyone![/quote]