Hi guys I'm Perfumic (aka Pilot VayneKing) I've been playing Vayne since Season 2 ranked, and Vayne is my most played champ for both Season 2 and 3. I played about 330 rank games with vayne in total. There may be things you think are wrong in this guide, but since most of the strategies are depending on your preference, you can leave a comment or something :). Thanks for reading.

After Vayne gets w, she has very high damage, so getting 6% lifesteal in the runes helps with her sustain in lane. She can start with a doran's and still sustain in lane for a while. (Many adc's start with 4 or 6 percent lifesteal nowadays, and it works the best with Caitlyn in my opinion, but 6% lifesteal works well with Vayne as well). Because my item build consists of getting a Last Whisper pretty early in game, we don't need Armor pen runes. It's better to bring flat AD runes. And most likely the opposing bot lane will have an ADC, so let's bring armor seals :)

I think masteries is pretty self - explanatory. You can change a few points in offense, but defense is pretty set for most ADC players imo.
Also, some may argue that it's better to take 9 utility than 9 armor, but that's usually not very good unless you like to play a very defensive lane. Contrary to people's belief, vayne is not terribly weak in lane phase now. The only ADCs you should watch out for are Draven and Caitlyn. The rest you can pretty much win or be even at the end of lane phase. Therefore, taking 9 in armor is better for small/big fights.

Some may think that being even at the end of lane phase is a disadvantage to you, but that's also not the case. Vayne is one of the most hyper carry ADCs in game along with Tristana, blue EZ, and Caitlyn(only if she has a nunu on her team). So if you meet cait or draven in lane, being even at the end of the lane phase (meaning similar CS count, and similar KD ratio - calculate the gold you both earned approximately, and if you are pretty much even, you're good.) will do you good late game. Don't worry too much about compare values of the AD value because Vayne's silver arrows add 'tons of damage'. And as such, Attack speed is important for vayne.

As mentioned in the skil note, up q at level 3 if you have to dodge many important skillshots like Leona's E or Blitz / Thresh Q or Lux Q for example. It lowers cd so you can tumble to dodge. If that's not the case and you're fighting alot pretty early in the game, you can up w first to max your damage. Whether winning or not, you need E at level 2 because you can push them away or use it for stun. It's important that you max Q first because it will max your damage. Match your Q damage with the 3rd hit of your W to max damage during fights.

I think this is the part most people look for in guides. Here's the reason for my build.

BOTRK - Ruined King.
Ruined King is a very good item for vayne. The range of it is similar with Vayne's auto attack range, so it's easy to use, and it gives attack speed and lifesteal which are both very important for vayne in particular. Also, it has an active that absorbs hp, which is important because for Vayne, damage isn't really a problem, it's usually the survivability and BOTRK gives a lot of survivability.

PD
As mentioned before, survivability is important for Vayne and PD gives you movement speed (as well as attack speed and crit)

Last Whisper
As you get higher in ELO, you will be focused alot. Usually the team fights (considering no one's been caught and you're fighting 5v5 head to head), the tank line - melee - will be on you. Lower elo players are always about "focus the ADC, Vayne why aren't you focusing ADC" but that's practically impossible to do when the tank line is on you. It's important you kill their tanks before their adc kills ours. Therefore after you get 2 core items, it's important you get LW to melt the opponent's frontline.

The rest
The rest is really up to you. If you're in a bad position in game and losing by quite alot and the opposing team wants to keep fighting, and thus you can never get enough money for a BF, it's also a possibility to get other items like AS items.
One important thing to remember is, you always need 1 defensive item no matter what it is (unless you're winning pretty hard).

As mentioned before, it's practically impossible for you, as Vayne, to get onto their carries in a ranked game (unless their team is totally stupid). Therefore just focus on killing the tanks that are on you. If their adc is onto you during a teamfight, you really can't do much. Tell your frontline people to focus their adc better.
But, if all goes well and our frontline is on their carries and their frontline is on you, here's a tip. If both your summoner spells are up, tell everyone that you don't need peel. Tell them to focus their carries and kill them before you die. If at least one is down, ask the support or jungler to peel for you. The reason you don't ask your teammates to peel for you when your spells are up is because Vayne is an exceptional kiter. Don't try to use your condemn(E) to stun the enemy. Push them away so you can survive longer and dps. Also, it's important to turn on your ult right when they get onto you so that you can get invisibility from R-Q. Also you have BOTRK so it'll help you kite better.

Tier 1
Nunu
Sona
Janna
Ali

Tier 2
Leona
Taric
Thresh
Lulu
Blitz
Nami

Tier 3
Soraka
Zyra
Lux

Counters:
Caitlyn
Draven

Easy Lane:
Ezreal
Kogmaw
Corki
MF