Azeroth = Earth, and The Great Dark Beyond = Outer Space.

Planets exist in the Great Dark Beyond as well as in the Twisting Nether.

Many of these worlds are said to’ve been (at least at the time of this game’s setting, which was tens of millions of years ago) on opposite ends of the Universe.

Known Worlds:

  • Centralis, a world whose inhabitants were slaughtered by Gorelix and the  [Maw of the Damned].
  • Draenor (Outland), a small planet located in a distant corner of the Great Dark[1] that served as the homeworld of the orcs, ogres, and other species, and as a sanctuary of the draenei. Destroyed by Ner’zhul, the remains of Draenor, called Outland, are no longer considered to be a planet as it sits between dimensions.[2]
  • Dreadscar Rift, a Legion portal-world situated in the Twisting Nether previously controlled by Mephistroth and ruled by the pitlord Jagganoth. It was conquered by the warlocks of the Black Harvest.
  • Fanlin’Deskor, a world annihilated by the Burning Legion.
  • K’aresh, the original homeworld of the ethereals before it was destroyed by Dimensius the All-Devouring. It was situated in the Great Dark Beyond, had at least two suns[3] and an arid landscape, and was home to several sentient species.[4]
  • Karkora, a world saved from Dimensius by the naaru T’uure.[5]
  • Mardum, a prison world created by Sargeras in the Twisting Nether when he still served the titan Pantheon. The imprisoned demons became the first members of the Burning Legion when Sargeras returned and shattered Mardum. The demons have used Mardum as a portal-world ever since as well, mainly for guarding the  [Sargerite Keystone], until they were defeated by the Illidari who took control of Mardum for themselves.
  • Nathreza, the homeworld of the nathrezim. It is located in the Twisting Nether.[6]
  • Navane, a world with a handful of intelligent races who held a history of enmity but united against the Burning Legion, until Kathra’natir turned them against each other with the help of  [Apocalypse].[7]
  • Nihilam, the “Doom World”, is a planet near where the Pantheon confronted Sargeras after the Burning Legion’s first destruction of a world. Sargeras proceeded to kill his fellow titans when they tried to reason with him, twisting and warping Nihilam in the apocalyptic conflict.[8]
  • Niskara, another Legion portal-world, home to the Niskaran inquisition.
  • Rancora, a Legion-controlled planet described by Portal Keeper Hasabel as “a landscape of festering pools and skittering death”.
  • Shadowgore Citadel was constructed on a “dead world” by the eredar assassin Akaari Shadowgore.[9]
  • Shar’gel, a world that appeared to the draenei to be a possible refuge during their journey on the Genedar, but the Burning Legion had laid in wait there and attempted to exterminate them.[5]
  • Tarratus, a prison world for rebellious demons.
  • Telogrus Rift, or simply Telogrus, is a destroyed, Void-infested world that has become the base of operations for the void elves.
  • Xandros, a world destroyed by Mongrethod on behalf of the Burning Legion.
  • Xerrath, destroyed by the Legion as a show of power during the enslavement of Xoroth.
  • Xoroth, the homeworld of the dreadsteeds, that came under Legion control.
  • Planets actively under attack by the Burning Legion can be accessed via Invasion Points found on Argus:
  • The Riftworld Codex that drops from Portal Keeper Hasabel can open portals to other worlds which provide one of three random effects:
    • Light of Absolarn, providing an absorption shield.
    • Flames of Ruvaraad, empowering the adventurer with shadowflame magic and dealing damage in a large area around them, significantly healing them for all damage dealt.
    • Winds of Kareth, providing a healing-over-time effect.

Draenor (Outland):

Draenor, which featured in Warcraft II: Beyond the Dark Portal, is the original homeland of the Orcs and a past home of the Draenei.

Draenor was torn apart when the Orcish leader, Ner’Zhul (later the first Lich King) opened dozens of portals to other worlds in an attempt to escape the invading Alliance Armies from Azeroth. The sheer number and combined power of the portals ripped Draenor into fragments and cast the remainder into the mysterious parallel dimension called the Twisting Nether, Home of the Demons. The remnants of the world are now known as Outland, and feature in the last mission of the human campaign of Warcraft II: Beyond the Dark Portal (though, without any actual terrain changes), Warcraft III: The Frozen Throne and more prominently in World of Warcraft: The Burning Crusade.[4]

An intact Draenor is the main feature of the fifth World of Warcraft expansion, Warlords of Draenor, which takes place 35 years earlier in an alternate timeline.

Titans:

Titans are awakened world-souls and thus each titan is a planet themselves.[10] Except for Azeroth and Argus, the details of what each titan’s planet was like are unknown.

Unnamed:

See for yourself the cruel, frozen void that lies beyond the margin of Azeroth’s skies!” – Star Augur Etraeus

The Burning Legion. Slayers of whole worlds. Could we hope to resist? Can you?!” – Star Augur Etraeus

These are the beings who will devour the future you so futilely fight to protect!” – Star Augur Etraeus

  • Star Augur Etraeus shows a number of unnamed planets to adventurers:
    • Four frozen planets.
    • A planet destroyed by the Burning Legion.
    • Six Old God-corrupted planets.
  • A small Legion prison world obliterated by the Void and left to rot.[13]
  • The Hara’samid sector and Xarodi sector are mentioned by Gezhe while speaking to a Consortium Nether Runner.
  • One demon world was invaded by a class order in an attempt to take it as their own.[14]
  • Illidan Stormrage and his demon hunters assaulted a demon world under the control of the pit lord Azgoth.
  • Right before Draenor’s implosion, Turalyon escaped with the forces of the Alliance Expedition that were with him through a portal to yet another world, one they could barely make sense of, before they returned to Draenor, now Outland.
  • Illidan traveled to three worlds destroyed by the Burning Legion while seeking out Nathreza:[6]
    • A desert with cemetery cities with bodies clogging the streets. Imps danced among the ruins. War had sliced the tops of hills and turned plains into sheets of glass. Mad ghosts haunted the land and mountains had been carved in the shape of dreadlords. A moat of bones surrounded a city the size of a nation. A giant skeleton rose from the moat and clawed its way over mountains of bones before the necromancy faded and the giant collapsed.
    • An ocean world with the water red as blood, filled with poisons that killed the whale-sized inhabitants. Massive rafts woven from dead kelp rotted on the surface with corpses of merfolk entwined around them. Sea creatures the size of cities decomposed on the ocean floor, surrounded by skeletons of aquatic armies that had once guarded them.
    • A desert world where he found the bones of wandering tribespeople. Every oasis had been poisoned. Dunes sometimes crumbled to reveal the skeletons of armored worms or remains of brass skyscrapers.
  • The unnamed homeworld of the aldrachi, invaded by the Burning Legion with the intent of recruiting the aldrachi. After Sargeras was wounded in single combat with the aldrachi champion Toranaar, he obliterated the few remaining aldrachi and ordered the Legion to bathe the planet in an inferno that would smolder for eternity.[15]
  • An “unremarkable world” that had already been invaded and pacified by the Legion, its leaders corrupted and its heroes slain. A child burning with righteous fury for his dying world crept into the Legion’s stronghold and killed Sargeras’ pet felhound, Goremaw, and several eredar guards while they slept. Sargeras was infuriated by the sight of his dead hound, and the world and all of its inhabitants were scattered as ashes in the Great Dark.[9]
  • A small, militaristic world which Sargeras had set his eyes on. Its inhabitants would have fought fiercely against a Legion invasion, but Sargeras believed them to be vulnerable to paranoia and fear. The newly empowered eredar assassin Akaari Shadowgore infiltrated the world’s strongholds alone as part of her first test. Within a month, the world had descended into chaos as tales of an unseen assassin spread like wildfire, and as heroes and leaders died silently, the world’s warriors broke into factions and blamed each other for Akaari’s assassinations. When the Legion finally revealed itself, the world begged to surrender, seeing an eternity of servitude as preferable to living in fear of daggers from the shadows.[9]
  • On a small world under siege by the Burning Legion, Gorelix and a team of mo’arg were tasked with building a citadel to serve as a base of operations. During one battle, this stronghold was attacked by the world’s brave defenders, and a massive breach opened in the wall. If not repaired soon, the the entire citadel would fall to the Legion’s enemies. Gorelix volunteered to defend the breach with the  [Maw of the Damned] while the other mo’arg worked. Hundreds of enemies, howling battle cries in their alien tongue, stormed the breach, but Gorelix stood fast, each kill infusing him with strength and vitality. When the last attacker had fallen, the other mo’arg found that they no longer needed to repair the breach, for Gorelix had filled it with corpses.[16]
  • An unknown world mostly covered in water depicted in the Halls of Lightning with two green-white continents (one in the southern hemisphere, the other in the northern hemisphere) and a purely white ice cap centered around the world’s equator.
  • “Countless” worlds that were judged and observed by Algalon the Observer.
  • “Countless” worlds visited by the titans, or the naaru, or taken over or obliterated by the Burning Legion.
  • According to Xe’ra, a “thousand thousand” worlds have been destroyed by the Legion.[13]
  • The draenei passed dozens of worlds and mapped much of the cosmos after they left Argus.
  • Several other seemingly gaseous planets seen in the skies of Outland and that are depicted in the Halls of Lightning and Ulduar.
  • At least seven planets were said to be set to feature in future patches and/or expansions for World of Warcraft, courtesy of Outland‘s Dimensional Gateways.[17]
  • After Sargeras is imprisoned and the Vindicaar hovers in the cosmos, several Void-corrupted planets can be seen.

Notes:

  • The demons of the Burning Legion destroy world after world. Every death narrows the range of possible futures for the universe, till eventually all the multitude of possibilities are narrowed to one, utter annihilation.[18]
  • According to Illidan Stormrage, there are only several worlds left besides Azeroth and Outland that were not completely annihilated by the Burning Legion.[19] After the events of the war in Draenor, the alternate Draenor is saved too.
    • Xe’ra confirms these statements, clarifying that there is only one of a handful of worlds left with life and that Azeroth is the only one that matters.[13]
    • However, according to Wrath-Lord Lekos, Azeroth is the last world standing, but whether the demon meant this literally or merely as a boast is unclear.
  • The term “world” generally refers to Azeroth itself, with other worlds usually being referred to by their names in context to Azeroth.

Placement:

  • Draenor was said to be on the far side of the Dark Beyond, and to have a red sun.[20] It is also described as being in a distant corner of the universe, as is Azeroth.[1]
  • Azeroth can be seen from the courtyard of the Black Temple in Outland, but the theory that Azeroth and Draenor may have been in the same star system has several problems:
    • Azeroth and Draenor orbited different kinds of stars. Azeroth has a single yellow sun, whereas Draenor had a single red sun.[21]
    • Draenor’s cataclysmic destruction would have been seen from Azeroth, but there is no mention of anyone observing it.

Details here.