Start with Boots and pots so that you have mobility and some sustain in lane. Although a doran's blade is a usual start item, this build is meant for late game domination. Simply put, if you can just farm under tower and are even in kills/deaths with the enemy AD carry by the 10 min. mark then you are probably going to win the game. Rush a BOTRK both for its active and att speed/lifesteal. Get boots lvl 2 next because its cheap and you need the movespeed. Follow up with zeal if you arent doing so well or a BF sword if you are doing well. Once you get your IE you should build a banshee's if you are getting burst down or a black cleaver/last whisperer if they are building armor. I personally like the black cleaver because of the extra hp, cdr, and damage you get (besides your w does true damage which means arm pen doesn't count as much as it would on other ad carries). I generally choose a banshee's because you have cleanse as a back-up for any cc that does get past the banshee's. Banshee's is more so you don't get burst down immediately if you somehow get focused by an ap carry. Finish up with a trinity. Why trinity? Because the spell blade stacks with the low cooldown of your q very nicely, the movespeed makes you harder to catch/allows you to line up condemn more easily, the slow proc works well with your passive so enemies cant get away, the extra hp makes you harder to one-shot, and the crit chance just adds to your damage. Overall its a great item on vayne. Using a phantom dancer or stark's shiv as a substitute is also viable if you are having trouble affording trinity force. However, if it gets to a late game full build, I would go with trinity over the other two.

This build makes you dominate late game. Thus, the arm per lvl seals and the MR per lvl glyphs help make you survive the later the game gets. The arm pen marks are just so you deal that much more damage. The lifesteal quints are so that you have more sustain in a fight. Although if you are playing vayne correctly you should not really be getting hit in team fights, it is still nice to have some sort of sustain in case you do. Flat arm and flat MR seals and glyphs can be used if you want a better early game. Flat damage marks can be used for the same reason. Movespeed, Lifesteal, Flat damage, Att Speed, and Arm pen quints are also all viable.

Once again this build is meant for late game dominance. Thus, I choose mobility over damage so that vayne is less likely to die. That's why I like choosing tumble. It provides some extra mobility and damage. The short cooldown makes it a great ability to farm as well. I choose w next so that you can harass with your q and w. Hit the enemy 2 times and then tumble to do extra damage. Get condemn by level 3 (get at level 2 if your support can stun). This will allow you to do massive damage if they get near a wall and more importantly stun them. I level this skill last because even at full level, the cooldown is so high that there is no way you're going to get off more than 1 condemn in low level fights. I try to level tumble first because of the mobility and it makes you that much more deadly when you get your ultimate. I get w next for the damage output.

Once again these spells are set for late game. I like cleanse and flash. Flash is all around good whether you are trying to wall jump to get away or just trying to follow an enemy for a killing blow. I like cleanse over the traditional barrier option because barrier does not prevent stuns. Although barrier is generally better for the early laning phase because it gives you extra durability, it becomes less powerful as the game progresses. Getting stunned in late game will almost always mean instant death for a squishy target like vayne (even with barrier). Besides you are supposed to always be outputting damage in team fights which cleanse will allow you to do better. Other options are ignite, heal, ghost, and exhaust. Ignite gives you sheer damage output without sustain which is more of a gamble to me. Heal is weaker than barrier for protecting yourself. Ghost can be shut down with slows or stuns. Exhaust can be good for both getting away and killing an enemy, but it is not as strong in team fights, as everyone will be trying to focus you.

The masteries are set to increase the max damage output and have some defense sustain.

Pros
-High DMG output
-a Stun
-Very mobile
-True damage and %HP damage
-Hard counter to tanky teams

Cons
-Squishy
-Weak early Game