For the Antweight Championships of both series of Robot Wars Extreme, a miniature replica of the Robot Wars Arena was built specifically to host those championships. Located in a corner of the Pits at the same filming venues as the other Extreme competitions, the arena was largely based on the full-size version of the Series 5-7 arena, complete with fully-functioning hazards. However, it was made at a reduced scale to accommodate the significantly smaller and lighter antweight competitors, which weighed no heavier than 150g.
The Antweight arena was based on the same design as the Series 5-7 arena, consisting of a rectangular floor and base surrounded by walls and featuring a façade based on that of the main arena. The façade featured mock control booths, entry gates and fans replicating the factory-style aesthetic of the latter, although it is unclear whether the entry gates were fully-functional. In Extreme 1, the arena was lit in a mix of red, blue, purple, yellow and green lighting, closely following the style of the main arena; in Extreme 2, only bright white lighting was used.
Competing roboteers controlled their robots directly in front of the arena, the sides of which were surrounded by tall plexiglass outer walls. Indeed, the aerials of several roboteers' transmitters were visible onscreen for much of the Extreme 1 Antweight Melee. The relatively low height of the inner walls, and the space between those and the outer walls, made it possible for robots to throw others out of the arena using the same methods as in the full-sized arena.
Some of the arena hazards present in the full-sized Series 5-7 arena were carried over to its antweight counterpart:
- The Pit of Oblivion was activated by a tyre-shaped button on the far wall, as with its larger counterpart, and was large enough to fit more than one antweight on occasions. Sometimes, it was possible for competitors to drive out of the Pit with assistance, as Combat Ant demonstrated during its Extreme 2 heat.
- The Floor Flipper differed from the full-sized version in that it was not only used to throw immobilised robots across the arena, but also fired on mobile competitors as with the later Series 8-10 version. The Flipper mechanism was also exposed, which resulted in Anty B falling into it after being lifted by the Flipper itself in the first series of Extreme.
- The Floor Spinner, introduced in Extreme 2, differed from its larger counterpart in that it was black and silver, and modelled on the original Robot Wars logo. Like the pit, it was activated by a tyre-shaped button on the wall opposite the hazard.
- All four Corner Patrol Zones (CPZs) were also replicated, although no additional House Robots were built for either of the antweight competitions.
- An alternative antweight arena design is alluded to in Robot Wars Extreme: The Official Guide, where it is stated that the main tactic for competitors is to 'try and shunt your opponent off the mini-arena platform', implying a Sumo-style arena. However, the arena referred to in the book is drastically different to the arena which was actually built and used for the Antweight Championships.