The undead, formally known as The Forsaken, are a race of creatures within the Warcraft video game universe. They made their first appearance as playable characters in Warcraft III, and then went on to be one of the five main components of what makes up the Horde in the
MMORPG World of Warcraft setting. They grew by leaps and bounds between the relatively wooden undead characters in WCIII to the fully player-controllable race in World of Warcraft.
Originally, the undead were the stereotypical shambling corpses, knowing only that they should destroy anything they could get their hands (or any other body part capable of handling should the hands be severed) on. As the universe within the games evolved, so did its races: the undead split into two groups, the Scourge and the Forsaken. The Scourge were, like any Hollywood zombie, largely recently-deceased corpses brought to unlife, as it were, by a powerful lich or necromancer. The Forsaken, however, are quite different. They possess genuine intelligence, agility, strength, wisdom, and even compassion for others. Also unlike the Scourge, the Forsaken have political ambitions—they formed, in part, the Horde, Azeroth's largest group of what many consider to be the world's evil force, and the only real enemy to the Alliance, who share population sizes, professions and, in some areas, land (such areas are universally designated "disputed").
The other branches of the Horde, with whom the undead form something of a quadriateral commission, include the orcs (originally aliens from another planet who came to Azeroth via a portal that the mage Medivh opened), the tauren (bovine and huge, the tauren are the only cloven-hoofed member of the Horde), the trolls (who look a bit like lithe orcs with hair, though they are largely blue-skinned to the orcs' green skin, though some areas harbor green-skinned trolls), and the blood elves (a splinter group from the rest of Azeroth's elves out of a lust for carnage, sorcery and treachery).
Like the Alliance's gnomes, the Horde's undead are generally considered to be "the cute race" by players, whereas the other races on both sides are of a more utilitarian appearance. The undead retains the trademark shambling, forward-leaning gait of more traditional zombies, but they're also able to run, jump, swim (indeed, one of their natural racial abilities is underwater breathing), and their small stature and emaciated figure (roughly 1/8th the mass of a male tauren) makes them a popular choice for the rogue class, or as a warlock due to their natural affinity for the shadow magic that warlocks deal in, though in the hands of the right player, they can excel at any of the classes open to them: rogue, warrior, mage, warlock, death knight and priest. A priest, you ask? It's true! During the early history of the Horde/Alliance conflict on Azeroth, the elves fought and lost a number of key battles, and the Scourge were able to capture (and turn into an undead banshee) who was perhaps the most politically important elf, Sylvanas Windrunner (whose name was borrowed from the Advanced Dungeons & Dragons "Faerûn" book, in which Sylvanus is the (male) god of rangers). Those undead that chose to enthrone and worship her caused the split between the two partisan groups of undead, with the Scourge eventually leaving to settle in the high elves' former home, Quel'Thalas, and the Forsaken continuing the fight, during which they built a home for themselves: the Undercity, beneath Death Knight Arthas Menethil's palace at Lordaeron, which is now in ruins and is the main focal point of the blight that covers the entire northwestern part of the eastern continent, collectively known as the Eastern Kingdoms.
As in most fantasy mythos, the undead were originally created by foul craft from elves and humans; in Warcraft's case, it was the high elves (the predecessors to the modern night elves and blood elves, of whom very few remain) and ordinary humans who were captured during the wars; they were enslaved and tortured by Arthas, the High Prince of Lordaeron and future undead ruler that was nearly as powerful as all the other big guns in the world combined as a Death Knight, and his untold thousands of minions. Before this time, Arthas, who many had seen as a benevolent and kind person, was growing increasingly paranoid about a plague sweeping through the area, turning its inhabitants into mindless undead. Fearing the further spread of the disease, Arthas led a campaign to raze the entire area, blighting vast expanses of wilderness, several towns and villages (Dalaran, Darrowshire, Corin's Crossing, Brill, Stratholme and Quel'Thalas to name but a few; these areas are now the Western Plaguelands (in which the undead stronghold/university Scholomance is located) and the Eastern Plaguelands (which contains both Stratholme, perhaps the least-difficult instance to conquer, and Naxxramas, widely regarded as the most-difficult instance (before the release of The Burning Crusade, at least), whose entrance is so well hidden that a large quest chain is required to locate it) and the Tirisfal Glades forest). The more Arthas flew into a violent rage, the more ripe he became for turning over to the undead he hated. Azeroth's most powerful lich, Ner'zhul, tainted Arthas' thoughts, urging him to purge more innocents, and eventually turned Arthas undead himself, but not before losing his own unlife and power to the immense and infinitely more powerful Arthas, who, it is said, now forever sits upon his throne of ice within the highly dangerous, bitterly cold and extremely treacherous realm known mostly in hushed whispers as Naxxramas, which floats, improbably, above Stratholme.
In appearance, at least in World of Warcraft, the undead look like... er, well, not to put too fine a point on it, but they look like goths with mild hunchback conditions. Among the hairstyles you can choose for your undead character include the "modified pixie" look for females and the "liberty hawk" for males, or pyramid spikes for both sexes, plus about a dozen others, all recognizable to anyone who's ever set foot in a goth club, with colors to match. The eyes of every undead glow a bright green/yellow. They seem paranoid, too, as even at rest they continually look to the left and right, stare at something, then stare at something else, following things imperceptible to anyone else nearby, like cats do. Their clothing is suitably ripped, torn and stained, and the chainmail or plate their warriors wear is noticeably dented and rusted, giving them that fresh "just out of the grave" look. Their skin color is a uniform gray/green, without much difference in hue from one undead being to another. Though every undead is born into undeath inside the tiny crypt in the tiny village of Deathknell, they can be found all over Azeroth and Outland.
Undercity itself is a huge, multi-level, maze-like metropolis, and it's very easy to get lost in for those not accustomed to its constant twists and turns. Despite its size, it has only two entrances and exits: there is a tunnel in the former Lordaeron palatial garden (the only part of the palace which still has standing walls), which leads down to an elevator, which finally deposits you at the bottom of the place, near the canals of green ooze that run freely around the sprocket-shaped city. Another aperture is an old sewer, accessible from the very bottom of Undercity and leading out into Tirisfal Glades, roughly a mile from the garden opening. A short distance inside the city is a bat roost, where one can catch a ride on a large and screeching bat to another bat roost in another area, and a short walk from the sewer exit is a zeppelin landing pad manned by neutral (neither Horde nor Alliance) goblins from the Steamwheedle Cartel (the Cartel operates similar options for travelers at many other places in Azeroth, not just here, and the only differences is that their operations for the Horde involve zeppelins, while their Alliance operations use ships at sea); the zeppelin near Undercity leads across the Great Sea to the land of Kalimdor, and just outside the orc/troll shared capital of Orgrimmar, within the land known as Durotar, a peninsula separated from the Kalimdor mainland (specifically Azshara, home of a great many nagas and blood elves), by the Southfury River.
If you've never played a Horde race before, the undead offer a good place to start as they're versatile in just about every class available to them. Players are unable to roll undead characters as shamen (they are the only Horde race unable to play a shaman), druids (night elves and taurens only), hunters (the undead, along with the gnomes, seem to be the only non-hunting races, possibly because the undead have the ability to consume their fallen (human) enemies to regain health lost in battle (obviously the gnomes don't do this)) and paladins (humans, dwarves, draenei and blood elves only).
All things considered, playing an undead character is fun. So far the only problem I've had is acclimitising to the acid-tripped/Frank Lloyd Wrong layout of Undercity, but I have a terrible innate sense of direction. If you're a claustrophile like Isaac Newton was, you should feel right at home there, but all things considered, I prefer Orgrimmar. And for completeness, the last remaining Horde capital cities that I haven't mentioned yet are Thunder Bluff, which is only sparsely populated, located on a large mesa in the center of the green, rolling steppes of Mulgore, which the taurens call home, and the stronghold Silvermoon, in the Ghostlands area north of the Plaguelands, inhabited by the blood elves.
World of Warcraft
Draenei | Dwarf | Gnome | Human | Night Elf | Worgen
Alliance Capital Cities
Darnassus (Night Elves) | Exodar (Draenei) | Gilneas (Worgen) | Gnomeregan (Gnomes) | Ironforge (Dwarves) | Shrine of Seven Stars (Alliance in Pandaria) | Stormwind (Humans)
Blood Elf | Goblin | Orc | Tauren | Troll | Undead
Horde Capital Cities
Orgrimmar (Orcs) | Sen'jin (Trolls) | Shrine of Two Moons (Horde in Pandaria) | Silvermoon (Blood Elves) | Thunder Bluff (Tauren) | Undercity (Undead) | Undermine (Goblins)
Neutral Capital Cities
Dalaran (both factions) | Shattrath City (both factions)