Hai I am a random (Silver 5) from the internet that probably knows nothing about league of legends but is here to share his wonderful knowledge of this godforsaken nooby world.

I've been recently (Sorry not a veteran) playing vayne for like 20 hours per day and high on redbull for 24 hours a day and had alot of fun learning how to say cyka in russian and how to actually play vayne.

From my hours and hours of experience, here's how I see vayne in the fields of justice.

Pros:
-You can 1v5 with super invisibility and ult
-Your team will praise you like if you're double lift if you do good (Respect)
-Armor? What is armor?
-Your DPS is pretty high
-Needs less peel than other ADCs (Be free)
-You'll be proud of yourself for mastering vayne

Cons:
-Very very VERY VERY weak early game
-Lots of laning counters that beginners could have a difficult time with.
-Your team will flame at you harder than the plane at 9/11 (don't kill me pls)
-You are VERY squishy (Aren't all adcs squishy)
-DO NOT PLAY IF YOU ARE NEW TO THIS GAME YOU WILL REGRET IT FOR LIFE
-Despite being not very peel reliant, still very reliant on support to initiate and take cc as Vayne is SUPER SUPER weak to cc compared to some other people who can still keep fighting without CC (She deepthroats alot)
-The Pros still outweight the cons just saying.

Vayne is a very farm reliant and early game weak champion, this means that if you want to use her spike (Max potential), you should have these supports that would be perfect for this situation.

Best Best Best Support Ideals:
Lulu: With a Poke, 3 CC abilities!, and an ult capable of saving you and giving you a free penta, this is probably the best for Vayne to lane with as it has everything needed to mouth feed vayne to be able to 1v5.
Thresh: Instead of Lulu, picking thresh is like a slight sacrifice of the free space vayne can have and maxing her potential mid game where you could definitely get her alot more kills with all the PEEEEL, CC, and utilities Thresh at his disposal, definitely a better pick if the Vayne is adept or Expert.

Karma: While not very Initiate like, she does definitely have a lot of poke and harass allowing Vayne to keep farming in early game securing her safety and chance to spike in Mid game. You have a snarl and slow so it makes condemn easier for your vayne.

When you start the game, YOU WILL NOT AUTOMATICALLY BE ABLE TO PULL DOUBLE LIFT PLAYS AND 1V5 AND WIN, THAT IS NOOB LOGIC. YOU WILL HAVE TO FOLLOW THE RULES OF FARMING AND AVOID ALL FIGHTS!(Yes I might totally be a girl for using such a cute image of vayne on a guide)

Yes, I said all fights, unless this is a decisive victory, you should stay back at all times and farm, and you should always use tumble to finish off last hits under tower so you don't miss any. Trust me, I got at least 20 more because I tumbled to finish off (That is the worth of one ENTIRE KILL) But still gotta be careful of that mana bar.

Let your support keep them at bay and warding while you get a much more freed up lane.

If you've been a good boy in lane and farmed all day for that BORK and boots and Zeal, you should be doing well maybe helping your team with dragon or steal dragon or just killing people in general.
You should have the item's I've listed, remember to always stay NEAR NEAR NEAR your support as if you have a Kalista tether together and if it breaks you both die. Your support will protect you all the way or else you are going to die even with ult and Q.

Woot this is where things get INTERESTINNGNGGGG. You now probably have most of the item's I've shown in the full build and doing bad or not, you are super and very crucial to the team (And they should be pretty damn scared by you)
But anyways, you should now stay with your team, wait for your top laner and jungler to go in and go for the carries on their team first, you can condemn away their Tanks if they are smart and have your support with you all times, after condemning their tanks, you can freely bork and rek the enemy carry as you carelessly fly around the battlefield screwing everyone's day up.

1. ALWAYS USE BORK WHEN ITS UP AND YOURE STARTING A FIGHT, OFTEN USE IT MID OF FIGHT ON THE ENEMY CARRY SO THEY CANT RUN AWAY BECAUSE YOU'RE THAT SCARY.
2. Remember to last hit properly, and if you played vayne enough you'll also know the amount of damage you do on each time you back.
3. Do not contest so much fights at the beginning of the game, you're just going to kill yourself.
4. If you're new, all you need to know is for the first 20 minutes of the game DO NOT FIGHT unless you're sure to get it like a 3v1 with your jungler, you and support against their lone support by the river.

If you're losing, just take a moment and have a deep breath first.

I can't necessarily tell you how to win, but you will first have to evaluate the situation, why are you losing and what can be the solution to why are you losing.

If lets say you've been shut down hard in lane because the enemy jungler bought a tent in your lane to camp and you've been careless and losing as their adc get fed. So this is when you should calling shots in your team and also rolling out with the support to get the enemy adc. Always remember to catch people who are running around alone by themselves as after killing them trying to contest a 4v5 wouldn't be really hard.

This is the key to coming back, but never be too confident in yourself.

That's about it, whatever rank you are, Bronze or Challenjour, I hope this guide helped you as my perspectives of vayne and I hope to see you people with a new guide on some other random ADC or something. Cyaaa! :D