I make this guide from observing pro players like Gosu,Doublelift and more. Im just an average adc in the ranked game. I played this game since Season 1 which is quite long. I make this guide because alot of players dont know what to build for Vayne.

Vayne can destroy tanks with her W, She is quite OP in the game when she's fed with kill or farm. Once you get BOTRK you can crush others adc if they are not fed. Playing vayne need alot of practice since you will need a fast time reaction of her ult.

Pros:
-Vayne has very strong kiting potential against champs that has no CC.
-She's one of the strongest adc in the game
-Snowballs very hard if you get early advantage.
-You dont need alot of mana on vayne because her ability is a low cost except for E(Condemn).
-You can easily solo alot of player if you practice hard.
-In low elos you can easily be a monster since she's hard to counter by low elos.
-Vayne is easier to learn than some other adcs such as Draven.
-No skillshot
-has a 1.5 stun that will give you advantage.
-Vayne's ultimate gives invisibility and damage.
-Chasing down will be no problem for vayne because of her passive
Cons:
-Assassin and apburster will easily crush vayne.
-Vayne is very reliant on the success of the team. She's hard to carry is the other team is quite fed.
-In early game vayne is one of the weakest adc.
-Vayne is hard to play agaisnt CC
-Range low
-Gets countered by support that have alot of CC.

The main idea for my build is to helps low Elo to kite agaisnt enemies. Zephyr and others have alot of movement speed that will helps you kite. Adding Furor on your boots will give u a slight movement speed boost while kiting. You can build Mecurial schmitar agaisnt champion like Zed that requires QSS (Quicksilver slash) to cancel his ult. Buidling Banshee for vayne is guide good agaisnt champion like Blitzcrank , Leona and more. Guardian angle is a must for vayne if they had no champ that will give you a hard time.

Thanks for reading this guide feel free to comment on below and rate it! :D