Abilities of Shaco
Spell skill priority is an important winning factor for Shaco. Understanding the abilities of Shaco in League of Legends is another. Below you can find all the relevant information on Shaco abilities. In order for item builds you should check the build for Shaco.
Passive: Backstab
Shaco's basic attacks and Two-Shiv Poison deal additional damage when striking from behind.
Deceive
Shaco becomes Invisible and teleports to target location.His first attack while Invisible is empowered, dealing bonus damage and critically striking if he attacks from behind.
Shaco teleports and becomes stealthduration seconds. Using Jack In The Box or Hallucinate does not break
Shaco's next Attack while totaldamage physical damage. If striking from behind, this Attack critically strikes for qcritdamagemod damage.
Jack In The Box
Shaco creates a hidden animated Jack-in-the-Box. When triggered, it will fear and attack nearby enemies.
Shaco creates a trap that stealths itself after e5 seconds and lasts for trapduration seconds. It activates when an enemy comes near or when revealed, Fearing nearby enemy Champions for fearduration seconds, or minionfearduration seconds for minions and jungle monsters.
Once activated, the trap fires at all nearby enemies for 5 seconds, dealing aoedamage magic damage, or stdamage damage if focused on a single target.
Jack in the Box's attacks deal an additional monsterbonusdamage damage to monsters.
Two-Shiv Poison
Shaco's Shivs passively poison targets on hit, slowing their Move Speed. He can throw his Shivs to deal damage and poison the target. The thrown Shiv deals bonus damage if the target is below 30% health.
Passive: While this Ability is off Cooldown, Shaco's Attacks Slow the target by slowamount*-100% for slowdurationpassive seconds.
Active: Shaco throws a shiv, dealing totaldamage magic damage and Slowing by slowamount*-100% for slowdurationactive seconds. If the target has less than executehealththreshold*100% Health, the shiv deals totalexecutedamage damage instead.
Hallucinate
Shaco creates an illusion of himself near him, which can attack nearby enemies (Deals reduced damage to turrets). Upon death, it explodes, spawning three mini Jack in the Boxes and dealing damage to nearby enemies.
Shaco briefly disappears, then reappears with a clone that lasts clonelifetime seconds and detonates when it dies, dealing explosiontotaldamage magic damage and spawning three mini Jack in the Boxes that trigger immediately. The clone deals cloneaadamagepercent*100% of Shaco's damage and receives cloneincomingdamagepercent*100% increased damage.
Mini Jack in the Boxes deal aoedamage magic damage, or stdamage magic damage if firing at only one enemy, and Fear for boxfearduration second.
FAQ on Shaco
What do you max first on Shaco?
Most Shaco pros max out 
Jack In The Box first.