5.23.12 You guys are right. IE should really be an option here. This build is intended to allow for solo barooning, and defeating that pain-in-the-*** thornmail (by mathematically eliminating the thornmail's effect). I'll add the IE, but remember, that's the same old build everyone else uses. In regard to the other notes, this guide is meant to be low-key and technical. I tried to spice it up a little but I AM a technical writer, so this will be bland and informative forever <3. Thank you all for your comments.
5.22.12 Guide Released
Master Yi is an all-around badass. I really do mean all around because he can play in any lane, in any role, and with any terrible team, and still do well if the summoner brings good skills and a decent measure of common sense to the table. AD Yi is the most common of the formats, so it's quite important to understand his function.
He is the most fragile form of Yi, so it's better to only play him if your team really has your back. Playing under the tower is always an option, but it may not be good enough if your lane partner is continuously pushing all the minions, or if they keep charging in a la Leroy Jenkins and dying.
Yi is a force to be reckoned with. Here's why:
Lots of damage
Fast movement (dat R)
Good in solo fights
Q great for chasing and farming, and also dodging skillshots if you're good
Passive is great if you watch and proc it
Yi can suck if you're not paying attention. Watch out for:
CC - You're squishy, and you rely on lifesteal
Thornmail - I'll talk about this later
Team fights - Get in, kill, get out, repeat.
Your ult - Cool down is about a minute if you don't get kills or assists
Ranged carries - These guys can ruin your day
Runes are pretty sweet. Unfortunately, AD isn't really too easy to add with runes. Instead, go for some sweet, sweet, armor penetration. I mean, do whatever you want, go ahead and do all strength runes and get the extra 15 or whatever damage, but it's usually better to grab some armor and MR. It's really a judgement call based on your play style. I've listed the runes I typically used when I started using Yi, and they made it pretty easy as long as I was cautious.
Get that damage. Don't bother with the utility field. I've never had a problem with the 21/9/0 set up above, but you could also do 9/21/0 if you REALLY have a hard time surviving (It might be a good idea in blind pick).
The basic build is up top. Unfortunately, there are going to be a lot of variables that change from game to game, and even from minute to minute. You'll need to roll with the punches and adjust your build based on what you're seeing.
This should be obvious. Start the game with a Vampiric Scepter and all you have to do is slap on some minions to restore your health. Plus it keeps you healthy while you're ganking.
These are your go-to boots. Attack speed is what keeps your damage constant and thus, your health from disappearing in the blink of an eye. Mercury's Treads are also not a bad choice, especially if you are up against some cc like, and especially, Sion, Riven, or Ryze. Boots of Swiftness are okay if you're trying to BD towers, but really not necessary unless there are some real speedy champs on the other team.
More of the good things you need to crush your enemies. The little move speed boost is also great to have. If you have a bunch of money, skip this and go for your The Bloodthirster, otherwise, just follow the order.
Your most doomy item. As soon as you get this, farm minions till the bonus damage and lifesteal are full. There's never a reason not to get a bloodthirster. Lifesteal is your health, armor, and MR. Get a second one later in the game and fill it fast, this adds 200 AD and 40% lifesteal. This is how you deal with any Thornmail.
Health, damage, and slow. All of these effects are coming together; culminating a whirlwind of damage, and making you as inescapable as a black hole. Go straight to the Frozen Mallet if you have the gold.
This is the upgrade for your zeal. No real need for explanation. Replace your Berserker's Greaves with one of these once you've completed your build. Your movespeed won't fall below 400, plus you'll do twice as much critting at a much faster speed.
No thornmail on the other team? Your team all did trust falls together, they're playing cohesively, and you want to do more damage with a bit less survivability. Dump one of those The Bloodthirsters for the IE. Combined with your two phantom dancers, you'll crit almost every time with 250% damage, which means you'll do your attack damage (about 400) times 2.5 (1000). You'll also be attacking about twice per second while your ult is up, meaning you do 2000 raw physical damage per second.
Tanky team to deal with? Grab one of these instead of your first zeal/phantom dancer. The only vulnerability is MR. Don't buy this to deal with one tank, because it's hardly worth the money if the rest of the team is squishy.
More stuff for dealing down a tanky team. Switch it with a Phantom Dancer. Really, any super armored team warrants this item.
If you're getting crushed by CC or high spell damage, this item could get you out of that jam. Keep in mind that it only blocks one spell per 45 seconds, but combined with Mercury's Treads it could be enough to keep you from going negative.
A great buy if you're getting busted down by a team full of AD, especially if they're ranged. It's usually best to replace a The Bloodthirster with this item if the other team has only one AP or less, but if there are more, replace your boots/ Phantom Dancer.
This is where everyone seems to stumble when it comes to Yi, because they forget that enemies want a good Yi to die. You will be focused every time in a team fight, so you need to single out the weak or separated enemies. Diving into a pile of enemies who haven't settled on a target yet will guarantee your death.
When the team fight starts, stay back a bit and start seeking out a target. Anyone who is low on health or separated by distance from the rest of their team is a good choice. Even if they're way back behind the rest of the team, you can use your Alpha Strike and get back there pretty quick, then run away at high speed with Highlander. Always pop your ult mid-flight when you use Alpha Strike, so you don't waste your ult, and you don't miss the CD refresh if you accidentally kill them with Alpha Strike.
Sometimes, the best thing you can do for your team is to be away from them. Yi is very fast, so you should be able to outrun just about any other champion with Highlander on, which is great for luring. You can also BD towers pretty easily with or without minions. If you want to BD, replace on of your The Bloodthirsters with a Warmog's Armor.
This is very simple. Yi, being a ninja, must follow a key tenet of martial arts: strike when the iron is hot. That is to say, you will develop an instinct for knowing when to attack. If it seems like a bad idea at the time, it probably is.
Remember also that opportunity is when luck meets preparation. Your preparation involves staying closer to your tower, and not overextending for ganks. Much like love, ganks are the hardest thing to find when you go looking for them; let ganks come to you. Score CS and cuddle your tower and lanemate. Hopefully, your enemy will become impatient, and then they'll dive and get murdered, or your jungler will show up and take their lives.
The key to being a Master Yi is not dying. Do not die. Do not. Level up as quickly as possible and buy up your items. Even if you don't make a single gank till level 11, you haven't hurt your team much if you haven't died. I often wind up being 2-3 levels ahead of everyone else on a bad team because I usually end games with 2-4 deaths at a max, and usually 14-20 kills or more.
In summary, don't push the minions, make last hits for CS, stay under your tower, and don't die unless you can take two with you.
It happens sometimes. You get a little too cocky early game, and your opponents just lay you out time after time. By mid-game you're frail and dainty. Go farm. Go anywhere. You can jungle anything by level 6 pretty easily. Wraiths are fast gold if you use your Alpha Strike. Minions go pretty quickly with auto-attack alone. Just keep an eye out for enemies, and be careful when considering attacking versus running.
AD Yi is a damage dealing doomsday device. Unfortunately, many players hate Yi. They say he's a "noob character" or that he isn't useful in a lane. Yi is a mid- to late-game specialist, and if you see a lot of squishy mages, you wouldn't be wrong to play him unless they deal a ****load of cc.
Remember that LoL is a team-based game. If your whole team thinks Yi is a bad idea, and they seem like they might know what they're talking about, take their advice. They might complain that you killsteal them constantly, but unless you're actively killstealing, you can just ignore that. Because you move so much faster than other champs, you'll have a far better chance of getting that final strike and the kill.
If you see it as a possibility, just run next to the enemy to see if a teammate can make the kill. If not, finish them. In ranked, don't play that ****, because your whole team is going to turn on you for pandering, especially if you don't make the kill. If a tank or support cries about your KS, tell them to shove it, and maybe put them on your ignore list.