8/8/11: I've edited the build order, getting lifesteal earlier, as well as delaying the second phantom dancer until after the bloodthirster, this way your survivability is increased dramatically.

Shaco is one of my personal favorites to play, he's one hell of an escape artist, does really good consistent damage, his ultimate confuses people when he doesn't have a buff on, and he's an all around nuisance to the enemy team, but only if he's played correctly.

Lane Shaco is tough to get used to, he's extremely fragile early game, which can make it tough to play him in lane, but i personally don't like to jungle Shaco, although he's extremely strong at ganking, as well as jungling (he can get dragon at level 6 easily) i just don't enjoy jungling him.

Pros
Great at ganking
Insane tower destroyer
Great at pushing
Amazing damage output
Amazing escapes

Cons
Squishy
Wards/Oracles counters his deceive escaping/ganking
Focused easily
Blinds HURT

So the runes on my guide are the runes i use, they're pretty much preference of player, but i find myself liking the bonus attack speed, the bonus dodge, and the MR runes i use most. Other runes that are always good to have are armor pen. marks, HP seals (my Shaco build is extremely squishy, so you may find yourself wanting the bonus health), and cooldown glyphs.

Masteries are pretty straightforward for an AD carry, the magic pen. is for Shaco's Two Shiv, because it DOES deal magic damage, even though it scales with both AP and AD.

Summoners are another personal preference thing, you could go exhaust ignite, flash exhaust, ghost flash (not recommended but it works), any combination really it's all preference, but i enjoy ghost exhaust, Why? Well Shaco already has a flash of his own, his deceive, and although, yes you will probably want to use it offensively, it's usually up fast enough to get away when you need it as well. Also, ghost is much better than flash in my opinion, if you throw on ghost and deceive, you're pretty much impossible to catch.

My item build focuses on critical strike, attack speed, Movement speed, and DPS. Madreds Bloodrazor, 2 phantoms, and my runes just barely keep your attack speed under the cap by the time you've got them, leaving you with about 2.46 attack speed, while giving you insane crit damage and crit chance, with great dps as well.

Madreds Bloodrazor is usually only purchased against a tanky team, but they're so great in any situation, 3% of a targets health with just under 2.5 attacks per second with your AD by the end leaves you practically 2-3 shotting squishies, and destroying tanks as well.

Bloodthirsters are just amazing items, they're always welcome in any AD carry's build because it's amazing damage and amazing lifesteal when stacked, and with your escaping skills it's extremely hard to lose stacks when you play smart.

The boots of mobility are for being able to scout the map with ease, run from lane to lane with insane speeds, catch up to enemies easily, and escape ganks easily, and that's pretty much it.

A lot of Shaco players get JIBs (Jack In the Box) first, and if that's what you like to do, go ahead, i find myself liking two shiv or deceive first, which you choose first isn't important really, but make sure to max two shiv first, then decieve right after, getting your ult whenever you can.

This is the most important part of playing Shaco correctly, a good Shaco can make or break a game for his team.

Your deceive is both a great offensive move and a great defensive move. It's a great chasing, ganking, escaping, blinking and damaging ability. When you use it offensively, you usually want to blink into their face, run behind them, and hit them from behind, this way it procs Shaco's passive, giving your crit an extra 25% AD to work with. It's also a great chasing ability, if someone's out of your two shiv range, you can deceive into two shiv range, use the shiv, run up, and attack them to death, just try to keep hitting them in the back for the bonus damage. The defensive aspect of this ability is the blink, you CAN deceive over walls, you'll have to test out certain walls for yourself, but he can hop most of them, also, there's one of the best juking mechanisms in the game, and this is how it goes, you're low on health, being chased, you used your two shiv but they're still on you and you're not sure you can get away, you use your deceive AT the enemies, and run the opposite way, that way the enemies keep on running the wrong way while you blue pill in the nearest bush.

Your JIBs aren't useless but i find myself not using them much, if you're being chased, and you're a bit ahead of the enemy, you can lay one down in front of you, and it will fear the chasers for a second when they activate it, and that can save you from death. Also if you have multiple JIBs stacked the fear is longer, so if you have, say, 5 in one bush, and you see someone approaching it, you can deceive to the bush, and have a free 5 seconds to hit the enemy, and all the while those JIBs are helping you out. Other than that i don't use JIBs for much else.

Your Two Shiv Poison is a great ability, it does a good chunk of damage, slows the target, and allows you to catch up to an enemy, or it can give a slow that can save you or a teammate from certain death.

Your ultimate. Probably one of the most interesting ones I've seen, but it does it's job well. It has many uses, such as killing a tower extremely fast, turning a gank around, escaping with low health, back dooring, there are tons of ways for you to use your ult. I mainly use it to take out turrets, because more turrets means more global money, which means more people getting items which means better chances to win.

Early game, you're weak, you are NOT a solo lane character, you are NOT good at holding lanes, but you ARE good at securing kills for your lane, and if you are laning, make sure you're laning with either a tank or someone who can take hits pretty well, because you're great at getting kills, but you're horrible at taking hits.

Mid game, you're starting to get stronger, at this point, if i haven't taken a tower by 10-15 min, i try to leave my lane to gank and push a different lane instead. You also should be able to take minions no problem, and you want minion kills badly, they are EXTREMELY important, because if you aren't getting a lot of kills, you have to make up for it by global gold, and minions. You want to get dragon around this time as well, call over a teammate or two and have them start off dragon so you can take advantage of your passive, and make sure you remember to get it as soon as or soon after it respawns, like i said with Shaco's ult, the more global money, the better.

Late game, if you've played correctly, you're strong, you may not have all of the kills, you may have a lot of assists, but you're still doing a ton of damage despite it, because you've been getting global gold and you've been farming minion gold as well, i usually finish out a game at the end of madreds because i don't back and we finish them off before i can buy the second zeal/phantoms, but i have gotten the second phantoms before.

In the end, Shaco is a powerful champion that can completely dominate a team if played correctly, and that can wipe out a turret in seconds late-mid game with his ult. He's a fun champion with some awesome tricks up his sleeve, an all around great champion.