"support shaco?"
"Shaco SUP?"
"wtf?"
"how does that work?"

These are just some of the phrases you will hear before queueing up with support Shaco. But if you do it right, you may hear this during and after the game:
"You made a believer out of me."
"Most annoying Shaco ever." (enemies)

The most important pieces of this are: 40% CDR + enough mana to use them skills.
Shaco has 4 abilities that can be used for escape. Here are their max cooldowns:
(6.6) Q - Invisibility + teleport
(9.6) W - fear trap
(4.8) E - passive slow on basics, slow on Active
(48) R - a clone

What does this mean? It means you will not die if you are continually using these abilities. You won't be able to withstand much damage, but you can dodge many types of damage with Q pretty easily, as well as tricking people into ulting your clone, etc.

Your role in the early game is to harass the enemy ADC and Support so much that they pay more attention to you and avoiding the bushes than your ADC, leaving him free to farm easily. You also set 1 box on the river side in case the enemy jungle wants to visit.

AP is recommended for abilities with ratio of 0.6 or more, while Jack In The Box (0.2) might benefit more from Magic pen, so choose your quints accordingly. Two-Shiv Poison and Hallucinate and R have 1.0 ratios so overall the AP quints help more, while Magic Pen could maybe benefit the first few levels of Jack In The Box.

Marks: Magic pen. No exceptions.
Seals: OPTIONS: mana regen, armor, health (or scaling versions of any of them).
Glyphs: OPTIONS: AP, MR, cooldown, mana regen (or scaling versions of any of them).
I have tried a little of everything. If you're brave/experienced, you can do full scaling mana regen seals and scaling cooldown glyphs. That way your items can be more AP focused and you'll hit your max potential faster. But not recommended in hard-hitting lanes.

QUINTS: You need 10-15 flat AP at the start of the game, you can get it from glyphs/quints.
OPTIONS: flat AP, scaling cooldown, scaling mana regen, flat mana regen, flat armor/MR.
You can use Magic pen quints if the other team is melee/tanky, because JITB benefits from it, but flat AP is better for E and R ratios.

Ferocity
Deal more ability damage.
Oppressor is a safe pick for E's passive and W's fear, so that your shiv's can do more, but I prefer Bounty Hunter because there's a strong chance with Mejai's that you aim to kill 3 or more champions per game.

If you want to go 18/12/0, Deathfire Touch is the only option, which will help your poke effect in the early game. Might be useful against healer supports.

Cunning
Cunning is the name of the game. Your important stats are mana regen and cooldown, that's how you will outsmart/outplay every opponent. The 45% cooldown cap is highly recommended for this. Your Hallucinate clone lasts 18 seconds. With that cooldown you can cast every 44 seconds, meaning only 26 seconds after the last one dies. A powerful clone explosion every 26 seconds will be unexpected, but you must have the mana to cast it.

Deceive - 6.05 seconds (stealth lasts 3.5)
Two-Shiv Poison - 4.4 seconds (slow lasts 2.0)
You can disappear, throw a dagger over and over again, cutting a squishy's health by 30-60% each time. In the late game it's just a matter of time to get the kills. Just beware of pink wards.

Stormraider's speed boost is only good if you're going to have the lead and can do 30% of their health with 1 dagger. Otherwise Thunderlord's is best.

Bandit is also great as a shaco support because you're melee and can occasionally score 10 gold with a Deceive hit.

Good supports take Ruby Sightstone.
GREAT supports take Mejai's Soulstealer.
For the new Mejai, you get a speed boost after 15 stacks, which is fantastic for getting in and out of the fight faster.

If everything goes right, you will be getting plenty of assists, which add 2 stacks (+10 AP) each. You lose 10 of stacks when you die. But CDR Shaco does not die. Helives to fight another day. The better you play, the more damage you do.
Mejai's Soulstealer is very gold efficient with enough stacks. Getting into the teamfight and detonating your clone will give you assist potential on all 5 enemies, so if your team wins, that's at least 10 stacks (+50 AP) Each champ you kill grants 4 stacks (+20 AP), and your E and R both scale at 1.0 ratios, making it very strong.


Morellonomicon is your other core item. I used to use Athene's Unholy Grail for the wonderful mana regen, but my strategy relies on avoiding damage and abilities, so magic resist does not interest me. I can Deceive away halfway through the combo when stun wears off.
+10% CDR and +50% mana regen from Forbidden Idol. Exactly the two stats that matter. It's cheaper than Chalice of Harmony, which doesn't give any CDR.
+20% CDR and +100% mana regen when Morellonomicon is complete. And a nice 80 AP. What seals the deal is the Grievous Wounds when your magic damage hits someone below 40% health. This will help against annoying tanks like Garen or Mundo or anyone who relies on their healing to get away.


Sorcerer's Shoes are the best since you intend to deal as much Jack In The Box damage as possible.
Rabadon's Deathcap is great with Mejai's Soulstealer.
Frost Queen's Claim wasn't good for sup shaco in Season 5, but with Frostfang's improved 100% mana regen and Queen's 150%, it's great for sustain, and has a fantastic ghost active to help in team fights.
I prefer using jitb and trinkets for vision, and the ghosts recharge within 1 minute, so you don't really need Eye of the Watchers.


The tricky items
By the time you finish your 4th item you might be close to winning the game, but if not, you have some options in finishing your build.

Item #1 - 10% CDR
You have 10% from Frost Queen, 20% from Morello, and your 5% rule-breaker from Intelligence , so you want another 10% to max out.

Will of the Ancients +80 AP, +10% CDR, heals for 15% of damage dealt.
Even if you're a pro at evasion, you'll take some splash damage in late game teamfights. So that heal does help sustain you and possibly even win trades when you factor the follow-up deceive.
Jack In The Box does not work with Spell Vamp. But Hallucinate's explosion toward the end of the game can easily be 600 (+300) magic damage. Even if 55% was blocked you would deal 400 damage to each and heal for 5% of that.

You can choose from other 10% CD items depending on your preference.



Item #2 - More AP
In addition to your core, Rabadon's Deathcap, and your 10% cdr item, you need a little extra AP to keep your skills scary. You might have a rough game and lose most of your Mejai stacks. At that point, it's perfectly fine to trade Mejai in for Rabadon or Void Staff.

I prefer Void Staff to deal with any amount of MR that is or is not built, +70 AP.
Alternatives
Abyssal Mask +70 AP, +45 MR, AURA: -20 MR to enemies within 700 range
Lich Bane +80 AP, +5% movement, +250 mana, PASSIVE: (.75 AD + .50 AP) on-hit after ability
Rylai's Crystal Scepter +100 AP, +400 health, PASSIVE: 35% slow single target spells
Liandry's Torment +50 AP, +300 health, +15 magic pen, PASSIVE: 1% health burn for 3s

Many champs have a specific skill to max first. In support shaco mode you sort of need all of your skills to hurt equally and skills are situational.

Deceive gets 10 mana cheaper per level (90/80/70/60/50). If you need to do a lot of dodging or disappearing, more levels will keep your mana costs down. It doesn't help damage much so try to favor the other skills. If you have enough mana regen and want to troll Thresh or Braum by dodging their stuff and counter-attacking, Level 2 deceive is good to take somewhere between level 4-7.

Jack In The Box is always first. Set two or three in the enemy's closest bush and wait next to them. If they walk in without warding, engage them with basic attacks. If they get shot by 2 boxes and your auto, it will burn them down fast. Poor Thresh! (Ignite is the best summ spell for these traps)
You might max this first or keep it even with Two-Shiv, but because it's less reliable, usually max E first.

Two-Shiv Poison is your harassment. Use it as soon as you see an enemy walking toward one of your JITB for max effect. Increase levels to make sure it stays effective if you notice that enemy Ezreal is handling it a little too easy. Frostfang does add to its damage.
MAX first so you can pick up those kills and start snowballing. The best SUP Shaco games are the ones where they surrender at 20 because they can't take the nukes anymore.

Hallucinate. Take this whenever you can, of course. Stand in the bush, clone yourself, send the clone out to pretend it's you and auto-attack them until he explodes. Great for safe turret diving low-health opponents. with 40% CDR you can make a clone every 48 seconds. Can help scouting around corners that aren't warded.
Also great if you need to make a tricky recall. Go into a bush, summon clone, start recall, and then carefully control the clone walking around so the enemy follows him. CAREFUL! If it dies and you right-click, you will cancel your recall.


Best sneaky combo: Make a melee enemy chase your Hallucinate clone into 1 or 2 Jack In The Boxes. Deceive in right after the clone explodes and throw a Two-Shiv Poison right in their face.
Satisfying for you.
Embarrassing for them.

Backstab is a great passive in its own way, dealing 20% damage from behind.
This will only really benefit you in chasing a fleeing enemy and throwing a dagger, since your Deceive isn't adding much damage to melee attacks.
JITB fear will often make the enemy turn away so you can time your E and hit them in the back for a huge damage bonus.

Flash is best. In combination with Deceive, you can hop over so many walls your opponents won't know which way you went.
NOTE: Some people say Shaco has Deceive and doesn't need Flash. This is true for jungle/melee shaco, but because you're building Mejai, I recommend flash for a double gap-closer or for a double escape, or for when you're too low on mana for Deceive.

Option #2:
Heal Gives you a speed boost and keeps you and the ADC alive if you're poked a lot.
Ignite With a Jack In The Box trap early in the game, this can get the kill
Exhaust trademark support spell
Because you're an aggressive support, your goal is max poke and even picking up kills, so I recommend ignite.

Possible others:
Teleport Anticipate recalling more often or want to roam
Ghost Extra escape/chase
These two are really an excuse to buy Distortion boots.

Above all, I'd ask your ADC what he wants you to take!

This will be most effective in Bronze and Silver queues.
Shaco's Jack In The Box does not have a lot of HP and gets shot down easily late game (RIOT needs to fix)

Shaco doesn't survive as well around pink wards. Bad for W and Q. And Stealth Wards give him away in the bush trying to Hallucinate bomb. More experienced players will fall for fewer tricks but you'll also develop more tricks with practice.

Pros
+ Great survivability
+ Good early poke/harass
+ Hard and soft CC
+ Built-in wards
+ Doesn't need lots of allied jungle help
+ Good peel for teammates
+ Fun gameplay
+ Aggressive
- High difficulty



Cons
- Squishy
- Damage can fall off temporarily mid-game
- Teammates won't forgive you if game goes south
- Very mana dependent
+ High difficulty

Magic Tricks


Deceive: Immortality
Not only do you disappear, you instantly travel in the direction of your click. TIP: Run from your opponent then without turning, cast Deceive in the opposite direction. To your opponent, it looks like you disappeared and kept running so they'll continue to chase while you backtrack to a bush behind them to recall.
+ or +
Use your Q to engage or disengage. They won't see you coming or going.



Jack In The Box: Death In The Bush
Experienced players should know better, but sooner or later they want to use the bush for security. That's when you strike.
But boxes also have short lifespans and minions can set them off by wandering too close to the bush.

Minions Place them close to the wall, or away from the lane minions. Your JITB are traps for champions, not minions. KEEP THEM OUT OF REACH OF MINIONS. In all lanes.

Ganks If you know the places junglers will walk to gank, put boxes in the pathway there. If the other team has champs that like to tower dive for the kill (Lee Sin, roaming Kat/LeBlanc), set a box behind your turret (where minions can't reach) and wait for them to dive you and get fear'd.

"Hallways" Just like with Teemo's shrooms, you know the enemy has to go through narrow jungle paths to get from one place to another. Hitting your JITB will not only reveal them for you but also deal them some damage.
Drop a trap in the river entrances just before your team does Dragon/Baron. If anyone comes to visit they'll have to go through your mini-clowns.

Lane/Push You're not necessarily built for this and clear slowly (except clone-bombing the waves), but if you have to push a lane out, ward up with boxes along the way.


Two-Shiv Poison: Slow Down
Big damage. Good slow. You have a passive slow on your auto-attacks while Two-Shiv Poison is off cooldown. If it's appropriate you can lead with that first before using the thrown dagger to slow them. But most often you should stay back and not melee with this build.
Aim for the squishiest target.
You can use this to peel for allies, peel for yourself, or chase down a kill/assist. In the endgame one of these can chop off 30% of an enemy's health.



Hallucinate: Seeing Double
Q: Should I ult now? A: Yes.
There is almost always a reason to have your clone in action. It costs 100 mana, so be aware of that, but you can send him to taunt people into jumping on him and blowing themselves up. He tends to shred about 50% of a player's health with an explosion.
Use him to scout for this reason also.
Big group of enemy minions and only you around? Send in the clone. He takes 2x damage from all sources, so they'll kill him fast while he stands in the group and then BOOM, lots of gold for you.

Because he takes 2x damage, enemies will be able to catch on when he dies too quickly. So make sure to chase them or lead the target's path and make sure they catch the fireworks.
Practice making him behave the same way you do, while you watch from a safe distance. It's important to stay out of sight and closer to the clone's limit so they think it's you.

Summon the clone before a dangerous recall. You can control him while you're in the bush recalling. Have him run around in the open so just in case they attack they get the fake version.

TIP: in bot lane, you can stand in the bush to see if enemy minions can see you. If they can, that means it's warded and they won't fall for your Clone.




Best sneaky combo: Make a melee enemy chase your Hallucinate clone
into 1 or 2 Jack In The Boxes. Deceive in right after the clone explodes and
throw a Two-Shiv Poison right in their face.
Satisfying for you.
Embarrassing for them.

In conclusion:

• 40% CDR (or 45%)
• Mana
• Harass
• Survive
• Repeat

Sweet dreams...

High Difficulty

Malphite he has a targeted harass like yours, and an annoying shield that refreshes if he doesn't take damage. Keep a jitb between you and him so you can poke harder. The new Deathfire Touch mastery also makes E damage linger for 4 seconds so it'll slow his shield from coming back up so fast.

Morgana - Q and W counter jitb, so does spell shield
Everything she has counters Shaco's abilities


Medium Lane

Alistar has a heal and can harass pretty hard, even knock you into a vulnerable spot, so save your Q for when you need it most

Annie has a rough combo and hard CC is bad news for Shaco. Might want MR for this one (chalice).

Braum He's melee and he's a tank but he provides a lot of damage reduction overall
I recommend baiting his Q with yours. Take 2 levels of Deceive so you can use it more often.

Fiddlesticks is Fiddlesticks. His goal is brush control too. Try to stay near your minions so his E doesn't hit you and your ADC as much. Burst him down whenever possible and try to keep the lane pushed.

Karma has good poke and a shield, but no heal. Poke her down over time with W,E combos.

Lulu Her Q and basic attack can hit jitb pretty hard so they'll have less time to deal damage, plus her shield.

Lux is always annoying. Try to force her to move into a Jack In The Box in order to get her skillshots on you and then counter attack.

Maokai has a hard engage and some bush control too, and heals himself. He's an even match in a solo lane but you have to be careful. Might need 2 levels Deceive


Healers are a little tough because they heal all the poke you put on their adc. So take extra mana regen to keep up with theirs (finish Morello before Mejai).
Nami
Soraka
Sona

Zilean A good Zilean can be extremely annoying and painful. But he's also naturally squishy. Set up good traps for him because he doesn't have any counters to jitb.

Zyra can be tough unless you keep her from zoning. Overall she's easy to get away from, just have to watch your positioning. She works well with their Jungler so don't get caught.



Easy Lane

The tanks are actually easier for Shaco to handle because they have to get close to deal damage. Teach them at level 1 to stay out of your bushes by stacking 2 jitb for them to walk into. They may fall below half health and from there you can control their position in the lane. Throw a Two-Shiv Poison every time they walk toward a box.

Blitzcrank - easy to dodge, can bait his grabs right before a Deceive
Leona - have your adc stay near a safe jitb, her engage will be broken when she reaches them
Taric - he can heal but he doesn't usually build MR either, build mana regen to outsustain
Thresh - hooks are easy to dodge, especially with Deceive