just played vayne and i bought rapidfire gun + phantomdancer first because the enemy team had 5 tanks and all just stacked hp so i thought i wont do much dmg with ad better get more ats for my w. but my support and top said that im trolling and that im breaking the rules because "ATTACK DAMAGE CARRIES NEED ATTACK DAMAGE!!!"
i then said my 3rd item will be botrk and they said "gg more attackspeed reported" is this really trolling?
Trídent5 voteslol u can build whatever you want
AS is also a lot more beneficial to Vayne than AD too XD
Also if the enemy team has 5 tanks you should get Blade of the Ruined King and Lord Dominik's or Executioner's later
FrankerX1 votesyea i kinda failed to get the botrk as 3rd item i admit that was horrible by me. so its fine if i get 3 attack speed items first as adc?
ps: can i report them for pinging me every 5 sec?
Trídent4 votesYes you can report them
And yes it's perfectly fine to get 3 as items as adc, adcs don't have to build straight AD, in fact a lot of ADCs would be useless if you just built straight AD. The people who were toxic to you had no idea what they were talking about
However, next time there's 5 tanks, I'd advise starting 
I'm no vayne main though xD
Ladayen2 votesAttacking fast is good.. but if you do no damage then it doesn't really matter how fast you attack. You can start with a phantom dancer, but then you need to follow it up with a pure damage item like Infinity Edge, and then after that you'll need lifesteal so a Bloodthirster would be good.
Botrk is not particularly strong late game so if you are going to get it get it first, then a speed item, then a damage item.
CrazedPorcupine1 votesBut on Vayne, where AS IS good, then why build AD? Once the tanks get thornmail, more AD is bad, more AS/LS is good.
I personally see no problem with the Vayne build if he was against multiple tanks.
Ladayen2 votesWell why is attack speed good on Vayne? Her W lets you do true damage every third consecutive hit. In a perfect world you would auto attack(AA) tumble AA again then condemn into wall then AA and tumble until enemy is dead. In a perfect scenario AS is pretty good. However you wont often get that perfect scenario so you need to be effective even with only one or two hits at a time. Combine this with the changes to thornmail last season it hurts attack speed more, as it now does bonus dmg per hit. This means that lifesteal is absolutely important. In order to lifesteal, you need to be able to compensate for that reflected damage, which means you have to do dmg.
EndlessSorcerer2 votesIt's not against any rules.
Not too long ago, the standard build for Vayne was Statikk Shiv into Rapidfire Cannon.
Vayne's ultimate gives her enough bonus AD to get through all-ins without building early AD.
No flash no life1 votesYou can play however you want as long as you aren't purposely losing the game. Plus back then I rushed botrk and zephyr on adc like vayne and kalista since both items gave ad and attack speed.
If not getting the optimal potential out of the team is against anything then I guess getting ap on malphite deserves a ban.
Dominick Destine1 votesIs this a troll thread?
FrankerX1 voteswhy is asking for the rules because im not sure trolling?
BladeSteel1 votesdon't pay attention to him.
SanKakU1 votesThey are reporting you for playing an attack speed carry instead of attack damage carry. Which is ridiculous because the only role that's locked in for the new draft mode is support. ADC/ASC/whatever else is not locked in so you did nothing wrong in that regard. There's something called blaming others for your mistakes, maybe that's what they were doing in that game. Blaming you for their own mistakes.
Wenderwall1 votesNo rules, free to build whatever you want to. I'll call you a troll but not report.
All the attack speed with base damage will never get even squishes. Like someone said is the first item highly recommended for vayne. It gives 40% AS + passive + active health steal. And then 2 more AS items (
,
or 
) and then anything else based on team comp.
Mama Soraka1 votesWhile its not against the rules a pure attack speed build on Vayne will never compare in damage to a more standard and balanced Crit/Ad/As build with Lord Dominick's Regard to help negate armor.
The true damage is a bonus and something you should work with when you can, obviously, but I've seen people try to justify build paths like PD first on her since her release day and that seriously weakens your laning phase as the big damage items like BF+pickaxe that the enemy has will easily out damage you and likely push you out of lane.
Naturally, the part about the enemy carry doesn't apply as much in the scenario you're talking about.