When Hulk was jettisoned away from Earth on a S.H.I.E.L.D. commissioned space ship, his intended landing place was a lush green planet devoid of any intelligent lifeforms. Unfortunately, the ship was sucked into a wormhole, and Hulk found himself on a planet where a corrupt empire oppressed barbarian tribes. Because the planet, Planet Sakaar, was situated so near the wormhole, there was a wide array of technology, and many different alien species. Captured by the empire, and implanted with a control slug should he decide to disobey, Hulk was thrown into the Imperial Arena to fight as a gladiator.
After surviving his first battle, one of the natives told Hulk that the Red King watching over the arena was the Emperor of the planet. Hulk engaged the Emperor in a duel. Though the Emperor began with the upper hand, the Hulk turned the fight around and cut his cheek. The Emperor sent the Hulk to the Maw, the most lethal gladiator school on the planet. The Hulk survived the initiation tests and was placed in a group with fellow gladiators Miek, Korg, Lavin Skee, Brood, Elloe and an unbound Shadow Warrior known as Hiroim the Shamed. Together, they defeated various challenges, and killed the Wildebot pack the Empire had been hunting down for months.
When the gladiators celebrated, they were interrupted by the Sakaar Democratic Insurgency, a rebellion that sought Hulk's aid in overthrowing the Empire. Elloe was the only one of the Hulk's group who joined, and the Insurgency was quickly detained. Hulk and his gladiators were sent to the Imperial Arena, where they had to survive three rounds in the ring. In the first round, the Hulk prevented a large bomb from landing on his teammates, seemingly sacrificing himself. A dying Lavin Skee led the other gladiators in a last stand, and the Hulk reappeared just as Skee died, killing the rest of the attackers.
The death of Lavin Skee drew the warriors together, and under Hiroim, the group was Warbound. In their final battle, they were placed against the Silver Savage. The Hulk, believing the Silver Savage was a friend, became enraged when the Savage attacked him. Fighting with the other gladiators, Hulk destroyed the Savage's implanted control slug and proceeded to nearly kill him. The final test put forth by the Red King was to kill Elloe and the other Insurgents. Hulk and his gladiators refused, but before the Emperor could kill them, the Surfer revived and destroyed all of the control slugs of the gladiators and slaves in the arena. Breaking out of the Arena, the Hulk led many others to freedom. A drop of his blood caused a flower rare to Sakaar to spring forth, leading some to believe that he was the prophesied Sakaarson.