Witch Doctor

Zharvakko the Witch Doctor is a ranged intelligence Hero who can take on the role of a support or a ganker. A master of voodoo curses and healing arts, he possesses several positioning-dependant crowd control/damage spells as well as a heal that scales well into the late game. Maledict is one of the most powerful damaging spells in the game, and is fittingly enough quite hard to hit properly - but when applied at the right time, Malediction can curse someone to suffer a slow, humiliating death as they limp back towards safety.

Tips

 * Try to wait on casting Death Ward in teamfights until the enemies have already used some of their stuns, making it less likely you will be interrupted.
 * Casting Death Ward from a hidden position such as the trees, or uphill in the fog, makes it much harder to disrupt.
 * At rank 1, Voodoo Restoration is the most efficient form of AoE healing in the game based on mana-spent-per-hitpoints-gained. It is often a good idea to invest a single point into this skill during early laning and then max it later after your other abilities once you have the mana regen to support the higher cost.
 * Paralyzing Cask is most effective when there are just two enemies close together. Under ideal conditions you can stun two enemies for up to 4 seconds each with this skill.
 * Paralyzing Cask allows the Witch Doctor to jungle effectively as it stuns neutral monsters for five seconds and deals extra damage.
 * Casting Maledict on opponents will often immediately force them to retreat for fear of taking crippling damage while under its effects. You can use this to make enemies flee who would otherwise easily kill you or your allies. If they do not flee, then at best they're trading themselves for you.
 * Maledict is a very weak and expensive spell at rank 1, and its damage only starts to kick in once you get it to at least rank 2 or 3. In very early game fights, don't worry about landing a rank 1 Maledict unless you're sure you can curse multiple enemies or you have enough burst to follow up.
 * Death Ward is an extremely effective spell against carries that typically rely on Black King Bar to stay relevant in teamfights, such as Luna, Gyrocopter, Lifestealer, Sven, or Dragon Knight.
 * Although Death Ward is easily interrupted, it is an effective zoning tool in teamfights that will either draw immediate attention from foes with important crowd control spells or force enemies to retreat from the area which the Death Ward resides in.
 * The Witch Doctor's early game damage and utility from Paralyzing Cask and Maledict are extremely strong in the laning phase. Consider skipping points in Voodoo Restoration until you reach level 10 to maximize lane pressure and damage output. Having a max rank Maledict as soon as possible allows you to pull off shorter duration Death Wards to secure important kills.
 * Paralyzing Cask stuns jungle creeps for five seconds, allowing the Witch Doctor to jungle effectively from around level 7 onwards. This is especially useful if you are falling behind or need to speed up a key item such as your Black King Bar or Aghanim's Scepter.
 * Paralyzing Cask stuns units in fog of war, meaning if you use a high enough level Cask on foes nearby jungle camps, there's a good chance it will bounce back to your enemies.
 * Consider getting an Orchid Malevolence as it combined with Maledict can bring any damage done to the affected enemy to massive proportions.

Trivia

 * Witch Doctor is sometimes called "The Walking Fountain", referring to his support skills Voodoo Restoration and Death Ward.
 * The Witch Doctor will sometimes say "Pills here!", referencing Left 4 Dead, another game made by Valve.
 * Witch Doctor's original name in DotA was Vol'jin, a reference to the character from the Warcraft universe.
 * Vol'jin is the chieftain of the Darkspear tribe, where the playable race of trolls in World of Warcraft originate.
 * Witch Doctor's fun name in DotA was Moose, taken from the player DL.Moose who played the Witch Doctor.