Hi! My name is Xervexos, and while I'm only Silver, I know quite a bit about playing Vayne. She's been my favorite champion since I started playing League a bit over a year ago, and even though she's been thrown under the bus a bit by the most recent patch, she's still very strong in the right hands, and can singlehandedly carry games. Her late game is very strong, but don't underestimate her early damage either - it can catch some people off guard. While difficult to play, she is extremely satisfying when mastered, and a good Vayne is possibly one of the most terrifying things that you can ever play against in League.

Pros:

Strong duelist
Extremely snowbally
Insane late game
% Max health true damage
Amazing at kiting
Stealth

Cons:

Difficult to master, especially the knowledge of your limits and being able to outplay your opponents
Squishy
Weak to AOE damage
Needs to have a cocky playstyle, and is reliant on taking calculated risks
Relatively weak early game

Rune for Vayne are fairly self-explanatory, the usual ADC runes that most players would run. AD marks add to your damage, and make CSing easier. Armor seals and MR glyphs give you some defensive stats to survive the early game. AS quints plus a few AS glyphs maximize your damage, especially with Vayne's Silver Bolts.

With the 6.1 buffs to the Ferocity keystones and the nerf to the armor penetration for the Precision mastery in the Cunning tree, Fervor of Battle seems like the most efficient keystone for Vayne. Because she is a champion centered around sustained damage as supposed to burst, Thunderlord's is now not as effective for the Night Hunter. However, if the enemy team is very squishy, I might still choose Thunderlord's over Fervor due to the accessibility to the flat penetration in Precision the preference to a bit more burst in your combo.

TL;DR - Fervor is better pick in 99% of games, but if you are against a very squishy team, Thunderlord's might be the better pickup.

Item builds on Vayne can differ every game - your build on any champion should be crafted to fit the game you are in. If you are only here on mobafire to blindly copy-paste builds to use in game, you are doing it wrong. The most effective builds are game-specific. For example, if the enemy has a high amount of burst magic damage, a Maw isn't so bad of an idea. If you are snowballing and want to end by 20-25 minutes, Youmuu's is great for quick fights where you will pulverize, and also gives flat armor penetration, which is great for killing targets without much armor. If the enemy team has something like an Amumu/WW/Malz ult, Ahri charm, TF gold card, or any QSS-able CC, grabbing a Mercurial is great. If you are going to be splitpushing a lot, grabbing a Botrk, Youmuu's, or PD early will help with skirmishes and duels. If the enemy team has a massive tank like Nautilus, Malphite, etc getting Botrk and a LW item will help shred their health and armor. If the enemy team has a lot of mixed burst damage that is difficult to avoid, grabbing a GA will help by giving you a second life. Everything about builds is situational, and crafting your build to your game will give you the best chance of coming out on top.

Now, I wanted to touch up on four items specifically, and why you would or would not build them on Vayne.

Last Whipser - Only against one or two super tanks like Malphite or Nasus - the LW + Bork combo will tear through them, but they don't help much against squishies, since it only penetrates through bonus armor. Of course, if you need a LW, choose whichever is more appropriate for the situation - if you are against Mundo or another champion with tons of sustain, you want Mortal Reminder, but if not then LDR.

Trinity Force - I never build this item until super late game, where I sell my boots for it. Due to Vayne's low base AD, the sheen proc is not worth sacrificing the extra AS or Crit of an RFC or PD.

Sterak's Gage - This item, in my opinion, is super underrated as a defensive item on ADCs. It gives a fat chunk of health, plus a shield, which together can effectively nearly double your health pool. This is on top of increasing your base AD, which goes great with Trinity Force.

Essence Reaver - Do not build this item on Vayne. She barely benefits from having 40% CDR, and would rather have attack speed. If you really want it to round out your 100% crit, just get Trinity Force.

Just like with your build, your skill order can change a bit depending on the game. However, all that really changes is when you put points into your Q and W - you always want to get your ult whenever, and forget about your E(#onepointwonder). Whether you max your Q or your W really depends on whether you need your to juke skillshots. If you are against a Blitz or Thresh, getting three points into your Q before maxing your W isn't such a good idea, if not outright maxing it first. However, if you do not need your for juking skillshots early on, maxing your W will give you more damage, so if you can, that is what you want to do.

Vayne's laning phase is sub-par compared to most champions, and her goal is to simply farm up and scale into the mid and late game. However, when coupled with an aggressive support in a good matchup, she can grab some early kills and snowball her lead.

Vayne's early trading is almost completely reliant on procing her W true damage, and there are a few quick combos that you can use to do so. The most common is AA > Q AA > E. This is a very quick, sudden combo that procs your W, gets a Q empowered AA in, and then distances yourself from your target. However, this combo is extremely mana intensive, so only use it sparingly. Another good trade is to quickly sneak in a Q empowered AA, hopefully catching your lane opponent off guard and allowing you to walk away without them returning any damage. To do this, you want to wait until right when they are autoattacking a minion, and when they begin their AA animation, you want to Q up to your max AA range and AA them. Because everyone has low AS early game, you then have time to walk away without them returning damage.

Once Vayne has an item or two completed, and gets some points into her Q and W, she can begin to either group up with her team to get objectives or splitpush. Her insane dueling potential makes her a great splitpusher, though if you never group the enemy team can group 4v5 and take advantages that way. Grouping with your team and fighting over objectives is key to winning any game of League, and as long as you were able to grab a decent amount of farm early you should be quite strong once you hit lvl 11, with either your Q or W maxed and the other having 3 points in it, a lvl 2 ultimate, and two items completed. By this point, you should have plenty of damage to shred through the enemy squishies and whatever tank items the enemy team has by that point.

The late game is the pinnacle of Vayne's power. You are a god, and everyone else is a mere peasant. Your job, at this point, is to stay alive and kill the enemy team. To do so, you need to take full advantage of your tumble to dodge and juke skillshots, and kite the enemy team into oblivion. One thing that I see a lot of bad Vaynes do is use your ult and tumble immediately into a fight. This puts you in danger, without a tumble to dodge anything for a whole two seconds. Instead, what you should do is walk into range, pop your ult, and begin autoattacking. If you need to gapclose towards a fleeing enemy, dodge a skillshot, or put some distance between you and an opponent, you use your tumble. Don't just waste its use on cooldown, unless of course you are being targeted, and in that case you want to make use of the stealth as much as possible. Ultimately, you just don't want to put yourself in too much danger - stay alive while outputting the maximum possible DPS. Your job is to deal damage, so do it!

Learning the inner-workings of Vayne takes time and dedication, and is much more than mechanics. Learning her requires game knowledge, calculated aggression, and the ability to outplay your opponent. Because of this, she is extremely fun and satisfying to play, and is difficult to get bored of. Good luck in your journey to learning how to play our beloved Night Hunter.