Vayne is one of the best champions of the League--if you play her right. A noob Vayne is a curse to the entire team. However a good Vayne that gets the right items nukes all enemy champs into oblivion, leaving them confused as to how Vayne could possibly win a 3v1 and have full health by the end.

Note that there's no way that you could possibly build all her items (they'll surrender before then), but this is what you would build if your game did get to that point.

Early game

Start out with your Doran's Blade. This gives you a good bit of lifesteal and enough health to keep you in your lane longer (also the reason for the armor runes). After you get first blood--or maybe just a kill--pick up your Berserker's Greaves to add some attack speed in the mix.

By the end of early game, you should have your Madred's Razors and at least start on Zeal.

Mid-game

Build up to your Trinity Force as soon as possible by getting Zeal, Phage, and Sheen in that order. After Trinity make sure you get your Vampiric Scepter, which is essential to stay alive as the game goes on.

Make sure to farm a ton during midgame (not hard for Vayne) so you can pick up your Recurve then Madred's Bloodrazor.

Late Game

If they haven't surrendered or disconnected because they're crying in the corner of their bedroom, get more kills (perhaps dragon would help) and grab your Bloodthirster.

Sell your Doran's if you haven't already and get the B.F., building into the Black Cleaver, then get Thornmail and sell your zerkers for a Phantom Dancer.

If it ever gets to that point.

• Vayne is dangerous against squishy champs early game. Exploit the use of her tumble to hit those types of champs.
• WHENEVER you see a low health enemy near a wall, condemn into it and kill. This will get you more kills than you can believe.
• Don't you DARE give up if your enemy runs away. Ult and tumble. Three hits and they're either dead or almost gone--from there you can tumble in again for the kill.
• Play aggressive, but only when you know you have protection. Vayne is squishy and prone to getting focused, so don't initiate with her.
• Frustrate the heck out of champs with deadly AOEs like Karthus and Rammus by condemning them away (preferably into a wall) and proceeding to rape them.
• Try to single people out as much as possible.