Battleworld is the name of a fictional patchwork planet in Marvel Comics.
The first Battleworld debuted in the Secret Wars crossover where it was created by Jim Shooter and Mike Zeck.
The second Battleworld debuted in Beyond! and was created by Dwayne McDuffie and Scott Kolins.
The third Battleworld debuted in Secret Wars #2 and was created by Jonathan Hickman and Esad Ribić.
Merged from dozens of fragments taken from many planets (including a suburb of Denver, Colorado from Earth) by the Beyonder, Battleworld was designed to provide an unfamiliar environment which nevertheless allowed all contestants to use their powers to the fullest. Many peoples, both alien and human, were brought along „for the ride“ by this method – it was because of this that Spider-Woman II was on Battleworld, as was Zsaji, the healer, who had brief romances with both the Human Torch of the Fantastic Four and Colossus of the X-Men.
In the aftermath of Secret Wars, the planet became infected with cosmic energy as a result of the Beyonder reclaiming his stolen power from Doctor Doom. This led to a „wish fulfillment“ phenomenon whereby force of will could alter reality such as repairing Captain America’s unbreakable shield or allowing Mister Fantastic to create a way to take them home extremely quickly. This is possibly either due to the Beyonder’s nature as an incomplete Cosmic Cube, which allows the wielder to alter reality around them by force of will, or was an aspect of the „heart’s desire“ promised by the Beyonders and granted to the default winners of the Secret Wars. All the heroes left the planet, except for Ben Grimm (who stayed behind because he was able to change to and from his human form while on the planet’s surface). Ben Grimm remained on the planet for a while in his own sideseries while She-Hulk took his place in the Fantastic Four, until eventually deciding to return home. Once he left, the planet had no more reason to exist, and so it broke apart once more. It is unknown if the pieces returned to their home planets or not, although the fragment of Colorado was ferried back to Earth with its citizens and the Secret Wars‘ villains by the Molecule Man.
A Battleworld appeared in the miniseries Beyond!. It was constructed by the Stranger posing as the Beyonder for the purposes of studying various combatants from Earth under the guise of battle. This faux Battleworld was destroyed at the end of the miniseries by the departure of the irate Stranger with Gravity holding it together long enough for his group to escape at the cost of his life. Although Gravity is later resurrected by Epoch as the new Protector of the Universe.
A third Battleworld appeared in the 2015 Secret Wars storyline, after the numerous incursions destroyed the Multiverse. The remains of several realities were all merged to form a new Battleworld with the planet having a roundish shape. All of these realities are known as domains and most have the ability to interact with each other. The Deadlands (which contains the Marvel Zombies), Perfection (which contains the Ultron Sentinels), and New Xandar (which contains the Annihilation Wave) are separated from the rest by the Shield because each contains threats that if loosed would destroy the other domains. This new Battleworld was created by its ruler Doctor Doom (who is worshipped as its deity God Emperor Doom) after he and Doctor Strange went to the Beyonders to stop an incursion of their reality. Although Doctor Strange didn’t kill the Beyonders during the confrontation, Doctor Doom appears to do so by using a secret weapon, actually thousands of Molecule Man, that allowed Doom to take the Beyonders‘ power as his own and incorporated the remnants of the realities destroyed by the incursions to create his own image of Battleworld with Strange unable to do anything else but to follow his words.
Each of Battleworld’s domains is ruled by an appointed „Baron“ or a „Baroness.“ The borders of each Battleworld domain are clearly defined and travel between different domains is discouraged, as it requires special dispensation from the local Baron or from Doom himself. Battleworld is enforced by the Thor Corps who serve as Battleworld’s police force who answer to God Emperor Doom. Battleworld is orbited by a small Sun, in fact the Human Torch, consigned to the role for acting against Doctor Doom, and Knowhere, that acts as Battleworld’s moon. Besides these two and Battleworld itself, there were originally no more celestial bodies in its universe, until Singularity, a mysterious young girl who actually represents a pocket universe that gained sentience during the multiversal collapse, appears to give her life to save the citizens of Arcadia from a horde of Zombies which made the stars appear in the sky.
This Battleworld would eventually collapse after God Emperor Doom’s Beyonders‘ power was transferred to someone more worthy (Reed Richards) who rectified the artificial reality.
As part of the All-New, All-Different Marvel event, it’s revealed that the reality where Battleworld was fashioned was identified as Earth-15513 and became a distorted portion of time and space after the destruction of the planet, however due to Battleworld’s reality having being the epicenter of this Multiversal renewal, it became rich in a substance known as Iso-8, a material identified as the byproduct of creation itself. When the Elders of the Universe of the restored Earth-616 realized that the Multiverse had endured a death and a rebirth, the Collector and Grandmaster discovered the remnants of Battleworld and resolved to fight for the possession of the Iso-8 and used the broken shell as the arena (known as Battlerealm) for their Contest of Champions, a competition where several individuals, taken from Battleworld and the reborn Multiverse, fought to the death on behalf of each Elder. The highest prize was the Iso-Sphere which contained within the Power Primordial, the concentrated and most powerful form of the Iso-8. After assuming control of the Power Primordial that the Grandmaster and Collector were competing for, the Battleworld version of Maestro recreates Battleworld to its previous form as he had previously vowed that he would become the God-King of Battleworld. In order to combat the remaining players, Maestro summoned the remnants of the Avengers and Thunderbolts from an alternate reality where Iron Man became President of the United States after winning the superhuman civil war as well as summoning Sentry of Earth-1611 in order to deal with the remaining Contest of Champions competitors. When the Iso-Sphere was stolen from Maestro by Outlaw, he used its power to banish Maestro away from Battleworld and teleport the contestants to wherever they wanted to be. As a consequence of Outlaw wishing that the Contest of Champions to end, the Iso-Sphere shattered. A group of the contestants decided to remain in Battleworld forming the Civil Warriors in order to guard the Iso-8 and the shards of the Iso-Sphere so they wouldn’t fall into the wrong hands.
The following is a list of the domains and the Marvel Comics event titles that are their basis or reimagining as fully revealed on Marvel Comics‘ Interactive Battleworld map in Secret Wars #2: