The Witch Doctor was - jointly alongside the Barbarian - the first class to be revealed for the game, back at the 2008 Blizzard Worldwide Invitational (the event at which Blizzard announced the game). At the event a number of skills were displayed, including early looks at some of his summoning and curse powers.
Witch Doctor art.
It was apparent from this early stage that inspiration had been drawn from the Necromancer class in Diablo II. Blizzard responded to comments regarding the similarities between the two by stating that, though they would share similar mechanics, the Witch Doctor had been designed to be highly distinct from the Necromancer class of Diablo II.
Jay Wilson, Game Director for Diablo III, in an interview with 1UP outlined the difference in approach:[0]
"I'd say that the Witch Doctor is not a reskinned Necromancer... Sure, they're both pet classes, but they don't operate the same. For the Witch Doctor, we wanted to create a class whose pets were not his primary source of damage output.
The Witch Doctor's pets are more of a distraction -- they're his form of crowd control. They're very transient, they don't matter as much to him, and they aren't really a primary source of damage. We wanted to have this general notion of a character who controlled all things slimy and gross, like zombies, bats, snakes, and spiders, but he didn't rely on them -- he just throws them out there.
One of his most permanent pets is his Zombie Dogs, and we have a spell to blow them up because they're just not that important to him. We consider Zombie Wall to almost be a pet as well; it's a short-term pet, but it's a pet nonetheless. Each element is like that, where it's another distraction while the source of primary damage is the Witch Doctor himself. This makes him play very differently than the Necromancer, which was intentional."
Much like the Necromancer, then, the Witch Doctor will avoid direct physical confrontations with foes, preferring instead to unleash summoned creatures to fight at his side, but unlike the Necromancer the so-called 'Zookeeper' style of build (whereby the player swarms the battlefield with weak summoned units to overwhelm enemies by sheer force of numbers) will not be viable. Instead, the Witch Doctor is concerned with summoning a handful of minions and using them to greater individual effect in combination with his other skills.
Aside from summoning abilities, the Witch Doctor also has command over a wide range of magic abilities and hexes/curses, which significantly weaken foes.
The Witch Doctor's Mana Orb.
The Witch Doctor is the only class in Diablo III to use the traditional Mana resource; a slowly-regenerating spiritual energy. Anyone familiar with Diablo or Diablo II will be familiar with the resource already, and so in some ways the Witch Doctor is the character class that most closely resembles the playing style found in the early games in the series. You cast spells which cost a set amount of Mana which is taken from your overall pool. The rate of regeneration can be varied by certain abilities and item modifiers, and the total Mana pool scales as the character levels up.
Female Witch Doctor concept art.
The Witch Doctor also has three unique item types at his disposal: Mojos, Ceremonial Knives, and Voodoo Masks. Mojos are talismans which the Witch Doctor holds in his off-hand (and are therefore not used in physical combat), Ceremonial Knives are well honed for sacrificial slaughter, and Voodoo Masks confer protection, whilst at the same time terrifying foes. Indeed the design of the Witch Doctor's overall armour is intended to frighten his enemies; it's typically covered with ancient skulls, feathers and horns, and consists of sharp body plating.
