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-dependent 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. Paralyzing Cask is a somewhat-unreliable stun that requires multiple enemies to bounce between to be effective, but can provide a barrage of stuns to the enemy team if they are grouped together. Death Ward has the potential to be one of the most damaging ultimates in the game so long as he is able to channel the spell uninterrupted.

Tips

 * It can be a good idea to build a Shadow Blade and use it exactly after casting Death Ward. Activating Shadow Blade won't interrupt Death Ward's channeling and it will make harder for the enemy team to interrupt your channeling. However, be cautious about enemies buying Dust of Appearance, Gem of True Sight, Necronomicon, or AOE stuns such as Warlock's Chaotic Offering.
 * Alternatively you can save money buy simply buying the Shadow Amulet alone. During the 1.5 second fade time you are able to issue any orders and they will be done without hindering invisibility from occuring. This is easily achieved with the double tap to cast on self option. When you are ready to place the ward, double tap the hotkey for your amulet, as you are about to fade place the Death Ward. Soon after you will be invisible and still channeling the spell. It's best to practise this technique with Maledict before attempting in a proper fight.
 * 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 level 1, Voodoo Restoration is one of the most efficient AoE heals in the game based on mana-spent-per-hitpoints-gained. It is often a good idea to invest a single point into this ability 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 ability.
 * 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.
 * 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 level 1, and its damage only starts to kick in once you get it to at least level 2 or 3. In very early game fights, don't worry about landing a level 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 Magic Immunity 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 Maledict at maximum level as soon as possible allows you to pull off shorter duration Death Wards to secure important kills.
 * 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.
 * If you plan to pick up an early level in Voodoo Restoration, it is often more effective to buy additional Clarity Potions instead of a set of Tangos or a Healing Salve

Trivia

 * Witch Doctor is sometimes called "The Walking Fountain", referring to his support abilities Voodoo Restoration and Death Ward.
 * Witch Doctor's last hit response Wdoc lasthit 05.mp3 "Pills here!" is a reference to Left 4 Dead, another title from Valve, where the players can notify the other survivors that they found pills. The survivors would say "Pills here" upon finding some.
 * Witch Doctor's original name in DotA was Vol'jin, a reference to the character from the Warcraft universe. Vol'Jin is the warchief of the playable race, the Trolls.
 * Witch Doctor's fun name in DotA was Moose, taken from the player DL.Moose who played the Witch Doctor.
 * His dying line Wdoc death 10.mp3 "Bad medicine.." is likely a reference to Bon Jovi's popular old classic Bad Medicine.
 * The line Wdoc kill 03.mp3 "Ask not for whom the spell tolls." is a reference to John Donne's poem "No man is an island".