This is my first guide, and it's on the first champion i have used extensively. I've played with Yi alot, and its the first champion i used in PVP. He's great early and mid game, and if he farms enough he'll still be good in late game. I've messed around with alot of builds on him, and this one works best to catapult you're team into victory while scoring a butt load of kills. As long as he gets what he needs early, he's a force to be reckoned with. I wouldn't recommend him for ranked matches mainly because he's squishy, but normal and bots he's a good champion. He's also excellent for twisted treeline. The guide is meant to help people learn the ropes of Master Yi and LOL before moving on to other, more versatile champions. I recommend reading this whole guide to get an idea of what this build is capable of. Also the stats up above aren't accurate considering the crit chance is at 0....so don't depends too much on that.

Below is a quick in depth detail of Yi for the impatient types.

This build focuses on attack speed and overwhelming the opposing team. Early on you want to take boots and 3 health potions and head to the top. Bottom is not good for yi; I've tried numerous times and it just doesnt end well. DO NOT BE AGGRESSIVE BEFORE YOU GET YOUR ULT. You can't die before level 6; if you can score a kill and scrape out alive then do it. Yi is'nt strong until he gets his phantom dancer, so farm farm farm! After level 6 try to unleash all your abilities on a champion; clear out your lane, and destroy a turret before recalling. If you dont get alot of gold in the beginning Yi won't survive late game, The main focus is to kill as many players as you can or help you're team so you can push. As you get into the double digit levels go jungle for the powerups and money; especially if the team is struggling as a whole. I know i listed more items then you can have, but thats because the bloodthirster is optional and sometimes isn't too reliable for Yi. I go with the berserker boots, phantom dancer, infinty edge, phantom dancer, frozen mallet and black cleaver/bloodthirster. i usually win before i need the frozen mallet and the last item. when you purchase your 2nd phantom dancer you could buy more crit chance items and attack speed. you're still guranteed to win(I've done it). The spells are meant to overwhelm a champion for a kill. ghost is good to run away or capture, and ghost is great to slow down someone using flash or ghost. I like the 21/9/0 mastery set. it's the most common and it works well. I hope that wasnt an overload of information, but its just a quick explanation for the impatient ones.

The biggest focus is on attack speed. Early on in game you want to get gold fast so you can buy your items and overwhelm the team. Physical damage is important too. It goes hand in hand with attack speed so you can overwhelm. The reason for the armor runes is pretty obvious; Master Yi's style is to kill and run and not be overwhelmed in damaged.

21/9/0 masteries. you can't go wrong with this. Offense is more important so Yi can kill fast and quick before he sustains alot of damage. I added masteries to health and mana becuase Yi has low mana and his health can be an issue.

Phantom Dancer- you can't go wrong with this, and you definitely can't go wrong with 2. I used to think one was enough until i bought two and saw the huge impact it had. The item as a whole benefits Yi greatly for his assassin build. If you're the type that likes having different items then trade the 2nd phantom dancer for a madred blood razor or a BF sword.

Berserker grooves- Good for the attack speed. Feel free to change these out if you need armor or magic resist. If you do this make sure you earn money fast for a phantom dancer.

Infinity Edge- The critical damage bonus is nice, and so is the attack damage you get. Tons of attack speed + damage=success. Alot of Yi builds use this mainly because it's a must have!!

Frozen Mallet- Attack damage and health, you ca't go wrong. Sometimes If I'm making a ton of money and doing well i get the frozen heart(One of the best armor items) The mana is a nice addition too. Both items reduce enemy attack speed too :]]

Black cleaver- reduces armor, atk dmg and atk speed. I buy this towards the end if i need money to blow since there are better early game items than this.

Bloodthirster- If you really like this item, get it after infinity edge. I normally don't use this or buy because i don't know what shape I'm in to use it in a game. If I'm doing good I'll consider buying it instead of the black cleaver.

I always take wuju style first because of its passive and then alpha strike, It seems more logical to me. I take meditate at level 3 so I can stay in longer. I prefer to max out alpha strike first so I can catch run away champs. Meditate I max out last. Health is'nt an issue unless you are really struggling; in which case you would max this out 2nd. I max my ult at the usual levels.

old pic

Exhaust- Great to slow down for ganks or stop the occasional runaway.

Ghost- You can exchange this for flash. I personally don't like it and prefer ghost but it depends on the person.

Heal- You have meditate to heal. Taking this would be a waste.

Revive- If you're dying and making this skill useful....lol. This is a waste of a spell IMO.

Smite- good for jungling. This build isnt for jungler Yi though :p

Teleport- Everytime I tried taking this spell into a game I never really needed it. Yi moves pretty fast, and this spell can be useful in those "omg my turret is being ganked oh my god wait yi is too squishy against all of those champions lol wut useless"...............o_o. I just prefer the others so i can harass.

Cleanse- I do in fact enjoy this spell. Of course you can just get mercury treads to wear off the stuns or the quicksilver stash. It all depends on the enemy team.

Clariity- Useful, but not for Yi. If you're having mana problems, get potions or the frozen heart build.

Surge- I never really enjoyed this spell. I don't use it because i enjoy the ghost/exhaust combo, but i may try in the future. It's your personal preference.

Ignite- Yi really wouldnt benefit from this. I tried using it. Lololol.

Promote- never used. seems stupid :/

Clairvoyance- nice, but you can just get sight wards or someone on your team (like ashe).

Flash- It's a decent spell. I have'nt really used it much. If you think this is better spell then by all means use it.

Pros
-fast attack + dmg= good offense
-crit chance gets insane
-get kills fast, overwhelm team
-turret DESTROYER
-agressive

cons
-squishy
-hard time agaist ranged and heavily armed champions
-not defensive
-kill steals will happen :O
-the whole team needs to know what theyre doing otherwise if you guys get overwhelmed Yi isn't good
-other team is fed....yi is bad

This build is all about being aggressive and overwhelming. The 2nd chapter in this guide provides a better summary to use him and what to do. Just remember to play smart and not TOO offensive otherwise you'll feed. If you're doing fantastic in a game, DO NOT GET COCKY. I've gotten cocky and because of that I lost a few games. Yi may not be a useful champ in ranked games but I enjoy him in normal and he's one of my favs. please leave comments/suggestions if something is wrong/etc! This is my first guide and I'm still a lol noob hahah. Please be nice:p