The Box, a massive cuboid structure, was conceived by the criminal mastermind Moralo Eval during the Clone Wars on Serenno. This structure was capable of transforming its interior into a multitude of configurations, from ray shields to flamethrowers. The Box was created to assess the capabilities of the galaxy's most skilled bounty hunters, with the goal of selecting those who would participate in the plot to abduct Supreme Chancellor Palpatine. Later on, its design served as inspiration for the Well, the testing ground within the Imperial Academy.
In the year 20 BBY, amidst the Clone Wars, Count Dooku, a leader within the Confederacy, orchestrated a tournament which took place on Serenno. During this event, Dooku and Moralo Eval extended invitations to a number of bounty hunters, including Cad Bane, Bulduga, Derrown, Embo, Jakoli, Obi-Wan Kenobi (under the alias Rako Hardeen), Mantu, Onca, Sinrich, Sixtat, Kiera Swan, and Twazzi. Of these, only five emerged alive from the Box: Bane, Derrown, Embo, Hardeen, and Twazzi, while the others perished. After Hardeen defeated Eval in combat, Dooku encouraged Hardeen to eliminate Eval, but Hardeen refused, stating that he was only there to fulfill his contract and receive payment. The five survivors, along with Eval, would form a group to work with Bane. Together, they would attempt to kidnap Supreme Chancellor Palpatine.
During the competition, Dooku and Eval had differing opinions regarding the effectiveness of the structure. Because Kenobi, unbeknownst to Eval, was participating in the Box, he was able to assist the other bounty hunters in surviving. This resulted in a lower fatality rate than Dooku had anticipated in the early stages of the competition, as he only required five bounty hunters to assist in the kidnapping of Chancellor Palpatine.
The Box's construction was likely a very costly undertaking, given its massive scale and ingenious design. Participants initially entered via a streamlined platform elevator, which transported the bounty hunters to the elevated structure. The interior contained a variety of rooms, each utilizing uniform squares covering the walls and floors to create obstacles. These squares varied in function from room to room. In the first room, white squares could rise from the floor, forming platforms to escape the deadly dioxis gas. These squares also served as video screens, displaying Eval's face as he explained the challenge. The exit was concealed within the floor beneath the gas. In the second room, darker squares could project from the wall, revealing orange laser spikes that extended outward. The key was to follow the pattern of the protruding blocks and use them as steps to reach the exit located on the ceiling. The third room contained a button that simply needed to be pressed to escape, but it was protected by an electric barrier. In the center of the room was a pedestal holding a syringe containing an electrolyte that would allow passage through the barrier unharmed, but it was poisonous to all but one of the competitors. As platforms rose from the floor, the lower steps would electrocute anyone standing on them. There was also a control room, where Eval and Dooku could observe the bounty hunters' progress, and Eval could adjust the Box's settings. Eval also possessed a smaller remote control that allowed him to modify the internal structure of the final room by raising or lowering square columns.