The King of Bots Arena was a large rectangular area which was used to host all robot battles for the shows King of Bots and This is Fighting Robots. Consisting of a 15m x 15m square with a 10mm steel plate floor and 7m tall outer walls, the arena was initially painted gray with red and blue squares at each end as starting positions for the competitors and yellow markings for some of the hazards. The arena in This is Fighting Robots featured a similar color scheme, although the red and blue squares were replaced with four black chevrons on each side, and most of the hazards featured red, blue or yellow markings.
In Season 1, the outside of the arena was decorated with large orange and silver clamps, which 'held' the arena with the aid of oversized 'robot arms'. There were raised platforms around the arena for judges, presenters and roboteers themselves. The roboteers were allocated places on opposite sides of the arena to control their machines - once they were ready for battle, they would pull a lever, attached to one of the arena's beams, which in turn would press a button to signify their participation.
For This is Fighting Robots, the arena perimeter underwent a complete redesign, with the outside walls forming an octagonal enclosure. On top of the roof, a set of four redesigned robot arms and a cylindrical scrolling LED screen were present; the latter showing the logos for the show and broadcaster Youku. Audience seating, hexagonal screens and corridors leading to the pits surrounded the entire arena, as well as an area containing a set of four chairs attached to robotic arms. These chairs were used by the celebrity team captains to watch battles from outside the arena enclosure, as well as to confirm participation in battles and select robots ahead of each battle. In the preliminary rumbles, the celebrities also had the ability to move their chairs forwards upon selecting a given robot during the battles themselves.
Also in This is Fighting Robots, roboteers and team captains were now allocated spaces on all four sides of the arena, due to the show's greater emphasis on battles featuring more than two robots. Roboteers allocated to each team would signify their robots' participation by placing a token shaped like their team logos onto one of four hexagonal sockets; the same tokens were also used by the celebrity captains to confirm their initial robot selections. Each socket is mounted on one of the arena support beams, taking the place of the former levers, and lights up once the token is fully attached, confirming the team's participation in battle.
The arena is filled with a range of different hazards to ether assist competitors attempting to immobilize its opponent or to give competitors an extra obstacle to avoid.
Sets of four pneumatic, cylindrically-shaped rods were located in the center of the arena, highlighted by yellow circles, and would fire up from the arena floor in groups of two. Their primary purpose was to lift robots which drove into or over them, suspending them off the arena floor for a few seconds. The rods could alternatively be used to trap robots in place if they drove in between the sets as they rose, such as Great White during its fourth-round battle against Chiyung Jinlun in Season 1.
In This is Fighting Robots, the rods were repainted with red markings and borders, and were one of a few hazards which could be controlled by the celebrity team captains during the main competition.
Opposite the floor rods, a set of four circular saws were also concealed in the floor within the center of the arena. The idea is that these saws would rise up and damage robots if they drove or were pushed over them by opponents. On occasions, the saws could also carry, lift and flip competitors over, with Chiyung Jinlun using one of them to re-right itself after getting turned over by Greedy Snake during their third-round battle in Season 1. All circular saws were highlighted with yellow markings in Season 1, and blue markings in This is Fighting Robots.
There were two sets of floor flippers, which faced one another, they are a set of powerful pneumatic flippers built into the floor, which could toss robots across the arena if they were positioned on it, it will fire on mobile competitors during battles whenever they drive or are pushed over it. This immobilized robots such as Scorpion and Crossfire during the course of Season 1.
In Season 1, from the second round onwards, the floor flippers were activated by members of the competing teams. An additional rule stated that teams must not fire their flippers until 90 seconds of the battle has elapsed - firing them earlier than this would result in a points deduction in the event of a Judges' decision. These circumstances resulted in Great White losing its fourth-round battle against Chiyung Jinlun, after its team fired a floor flipper on the latter 13 seconds earlier than the allowed time.
In This is Fighting Robots, the floor flippers were marked with two blue outlines, and were one of a few hazards which could be activated by celebrity team captains during the main competition. Notably, Yellow team captain Sa Beining activated one of the flippers to impede Sandstorm's initial attack on Chronos during their battle in the second round.
There were a set of five flame jets in two isolated areas near the top of the arena, shooting flames with temperatures of 1000 degrees Celsius. Their function was that they could cause damage to robots' internals and set flammable materials on fire whenever a competitor drove close to them.
As with the floor flippers, the flame jets could be activated by celebrity team captains during the main competition of This is Fighting Robots.
Several rows of spikes lined the side walls, each weighing 15kg. A robot could push its opponent onto these spikes to try to impale them, and could even cause severe internal damage once a robot was rammed into them. Alternatively, competitors armed with lifters, flippers or vertical spinners could place or throw their opponents on top of the spikes, leaving them stranded for an instant knockout victory.
A disadvantage to these spikes were that they could get bent and damaged quite easily by a massive ram, or be completely ripped off by high-powered spinning weapons, as demonstrated by Megabyte in its Season 1 battle against Stingray.
The spikes were left largely unchanged for This is Fighting Robots, although two of the walls featuring them were repainted yellow.
There were a set of two drum blade "grinders" that were featured on either side of the arena. Famously referred to as gnargalators by Team Robo Challenge, these hazards were intended to damage, flip or even crush competing robots if they drove or were rammed into them by opponents. Competitors armed with grabbing or crushing weapons, most notably Greedy Snake and Spectre, often used the grinders to inflict damage to opponents after grabbing them.
Sometimes, it was possible for the grinders to carry robots over, resulting in the affected robot being left stuck in the space between the grinder itself and its mount, leading to an instant knockout loss. This happened to Whirlwind in its Season 1 second-round battle, after Spectre lifted, carried and lowered it onto one of the grinders.
A set of three hammers were located in the corners of the arena, with foam heads weighing 60kg each. Competitors could push their opponents near the hammers, allowing them to damage opponents' armor and internals by repeatedly hitting them from overhead.
In This is Fighting Robots, only two hammers were used, mounted on opposite sides of one of the grinders.
In Season 1, from the second round onwards, competing teams could activate a smokescreen in front of each other's control areas, briefly obscuring the drivers' vision. This fog is not launched inside the arena itself, but directly in front of the control area for a short period of time.
For This is Fighting Robots, a pit was added to the arena, consisting of a large, unmarked square panel located in the center which robots could fall or be pushed into. Although initially closed during the preliminary battles and first two rounds of the main competition, this hazard was made active in the third round, and was lowered at the start of every battle in this round.
If competitors drove into or were pushed into the pit during the first half of a battle, the pit could be raised back up after several seconds to let them re-join, their ascent heralded by flashing lights. Once a robot was freed, the pit would lower again; any pittings after this would result in an instant knockout loss for the affected competitor, regardless of whether or not they had been pitted earlier on in the battle.
In Season 1, Ling Zhou would also make her robot introductions within the arena, and interview the combatants outside of it. The winners of Judges' decisions would also be announced with all teams present inside the arena. A similar precedent was evident in This is Fighting Robots, where the show's presenters announced the outcome of battles - including Judges' decisions - from various places inside and outside the arena.