Robot Wars Arena

The Robot Wars Arena is a large rectangular area within the Robot Wars television studio which was used to host all robot battles. In Series 7, the arena was approximately 32x48 feet (roughly 9.8x14.6 metres) and was enclosed in a huge clear plastic box 20 feet (about 6.1 metres) high, with arena walls approximately 0.5 metres high. There were assorted hazards in the arena, some that changed from one series to the next and others that remained constant. Since the start of Robot Wars, the look of the arena changed several times, due to the different studios the series were filmed in.

Originally, the arena was located in a warehouse in the Docklands, London. This setting was used for the first two series of Robot Wars, but this site was cleared to make way for the Millennium Dome. The set used for Series 3, a studio at Elstree Park, proved to be too small, so a new location at Park Street Studios (near St Albans) was found for the filming of Series 4. This also had to be razed to the ground, so for Series 5/Extreme 1 the show returned to Elstree but for Series 6 onwards, it was moved to the former RAF Newton base in Nottinghamshire. Filming of Series 8, 9 and 10 of Robot Wars took place in Glasgow.

In 2005, the new owners of the former RAF Newton base discovered the custom made set in the basement of the air base. They notified the property agents, but received no reply. With no use for it, the owners threw out the set - valued originally at £11,000 - and had it scrapped for £250. Robot Arenas Limited (who had bought the arena from Mentorn) claimed legal action against the new owners, claiming wrongful destruction of the tailor-made set. However, Deputy Judge C Edelman rejected their claim in February 2010, ruling that the new owners of RAF Newton had "acted reasonably", and that the set only had "scrap value" anyway.

The new Robot Wars Arena for the rebooted series was built from scratch, featuring 6mm steel floor boards instead of the typical wooden boards from previous series, and is 15x15m in surface area, enclosed in a 20x20m polycarbonate box. It was designed by Robo Challenge.

1st Arena

 * Filmed at: Docklands, London
 * Series appeared: Robot Wars: The First Wars & Robot Wars: The Second Wars

2nd Arena

 * Filmed at: Elstree
 * Series appeared: Robot Wars: The Third Wars

3rd Arena

 * Filmed at: Park Street
 * Series appeared: Robot Wars: The Fourth Wars, MTV Pilot

4th Arena

 * Filmed at: Elstree (Series 5, Extreme 1, Extreme Warriors Season 1, Dutch Series 1), Shepperton Studios (Extreme Warriors Season 2, Nickelodeon), RAF Newton (Series 6-7, Extreme 2, German Series, Dutch Series 2)
 * Series appeared: Robot Wars: The Fifth Wars, Robot Wars: The Sixth Wars, Robot Wars: The Seventh Wars, Robot Wars Extreme: Series 1, Robot Wars Extreme: Series 2, Extreme Warriors: Season 1, Extreme Warriors: Season 2, Dutch Robot Wars: Series 1, Dutch Robot Wars: Series 2, German Robot Wars

Antweight Championship Arena
A miniature replica of the 4th Arena, built specifically for Extreme 1-2 competitions featuring antweight robots weighing 150g and under.
 * Filmed at: Elstree (Extreme 1), RAF Newton (Extreme 2)
 * Series appeared: Robot Wars Extreme: Series 1, Robot Wars Extreme: Series 2

5th Arena

 * Filmed at: Westway Park, Renfrew, between Glasgow and the airport
 * Series appeared: Robot Wars: Series 8, Robot Wars: Series 9, Robot Wars: Series 10

Doors and Entry Gates
In the first two series, the arena façade featured a pair of sliding doors forming part of a large Robot Wars logo, where all robots would enter from the pits and competitors would drive through during their on-screen introductions. The area between the doors and the arena itself would also act as a starting zone for The Gauntlet and some Trial events, occasionally with a revolving turntable or mesh pen added. For Series 3, the arena featured a single large gate for all robots to enter, complete with a large ramp which enabled teams to carry their robots through the gate from the pits. An entrance ramp was still present in the Series 4 arena, even with the introduction of entry gates on the front façade. From Series 4 onwards, the single gate was replaced with three entry gates on the arena façade, where competitor and House Robots would drive through to get into and out of the arena before and after each battle. Each gate was labelled with a letter - Gate A (left), Gate B (middle) and Gate C (right) - with only Gates A and C being available for competitors between Series 4 and the second series of Robot Wars Extreme. Gate B was reserved for the House Robots during those series, and thus often became referred to as the House Robot Entrance, although all three gates were made available for all robots to enter through in Series 7.

The Series 8-10 arena arena features three entrance gates positioned halfway along the left, right and far walls. These gates lower into the ground and allow robots to be brought (or, in the case of the House Robots, driven) into the arena, in effect also serving as the backdrop for all robot introductions in the new series. The contestants enter through the side walls, the House Robots from the rear wall. These entry gates, alongside the empty area behind the pit release button, are the only parts of the arena wall where there are no 7ft polycarbonate screens mounted on top. This makes them strategically important as the only places where out of the arena flips can be realistically attempted.

Pit of Oblivion
The Pit of Oblivion is a square hole in the arena floor, measuring about 10 square feet or one square metreinto which a robot might fall or be pushed into for an instant knock-out victory. It could be considered the arena's "signature" feature over the course of the series.

Debuting in Series 2, the Pit was originally an open black hole filled with tyres. Whenever a robot fell in, a large plume of smoke would emerge from the Pit, signifying a robot's defeat. The first robot ever to fall into the Pit was Tantrum, during the Tug of War Trial in Heat B. However, the first instance of a robot being pitted in battle occurred in Heat E of this series, in which Technophobic was defeated this way by Killertron in the Heat Final. In Series 3, the Pit largely resembled its Series 2 form, but was only open during the first two rounds of each Heat, being closed off for the Heat Finals and all subsequent rounds thereafter. During this series, it also produced sparks instead of smoke whenever a competitor robot fell in.

In Series 4, the Pit was completely redesigned, now consisting of a square panel with black and yellow hazard stripes and a red outline, an appearance it would maintain for the remainder of the original series' run. In this series, the Pit would be closed at the start of a battle, allowing robots to drive over it in the initial moments. After a certain amount of time had passed, usually 100 seconds or earlier if a robot was immobilised quickly, the panel would open, its descent heralded by a siren. However, this siren was actually a sound effect added in post-production, and was not audible to the roboteers. Consequently, many self-inflicted immobilisations were caused by the drivers not noticing that the Pit had opened. For Series 5, Dutch Series 1, the first series of Robot Wars Extreme and Extreme Warriors Season 1, the Pit was activated by a button (alternately known as the Pit Release Button (UK Series/Extreme) or Pit Trigger (Extreme Warriors)) which competitors and House Robots could press in order to open it. In the aforementioned series, the button took the form of a yellow tyre mounted on the arena wall directly opposite the Pit. In Series 6 and all international series thereafter, the tyre was replaced with a red metal bumper, only to return for Extreme 2 and Series 7 with a slightly different design to that used in Series 5/Extreme 1. Additionally, the siren used to signal the Pit's descent could now be heard inside the arena, instead of being a post-production sound effect. During Extreme Warriors Season 2 and Nickelodeon Robot Wars, the release bumper was mounted noticeably further away from the Pit than in the UK, Dutch and German series, and was painted black with black and yellow hazard stripes. Occasionally, the tyre/bumper would become dislodged or knocked off the wall if robots drove into it too quickly or too violently - sometimes it was destroyed or flipped out of the arena in the process. As in Series 2 and 4, a large plume of smoke would ascend from within the Pit as soon as a robot fell in. Only two robots managed to escape from the Pit throughout the history of Robot Wars so far, although these instances took place outside of the main series competition. Stinger escaped during its Series 4 Pinball Warrior run, although the pit was not lowered completely, while Combat Ant was flipped out of the antweight pit by Hades during its Extreme 2 Antweight heat, with Hades also being in the Pit at the time.

The last robot to fall into the Pit in the original series was Tough as Nails - a robot notable for its tactic of grabbing and pitting opponents as quickly as possible - which was pitted by Storm 2 in the Semi-Finals of The Third World Championship. The Pit returned as part of the Series 8-10 arena, once again activated by a release tyre button which robots can press. The Pit now descends far quicker than in previous series, and is significantly larger than before (indeed, Behemoth was able to drive very slightly inside the Pit after being pushed there by Carbide during their Head to Head battle). The interior walls are now decorated with small lights, and a series of warning beeps replace the siren formerly used to signal its descent. For Series 8, the smoke pyrotechnics were discarded; however, they returned for Series 9, starting with the Battle of the Stars celebrity specials. Here, they form a mist which emits as soon as the Pit is opened, rather than an explosive plume when a robot falls in. During Battle of the Stars, the pit was also shown to descend automatically when a defeated competitor was being attacked by a House Robot after 'cease' was called.

Arena Tyre/Dial Of Doom
Series 9 also introduced a new function for the Pit release button, which was also referred to as the Arena Tyre for this series. The space behind the button was occupied by a dial, which would swing left or right once a competitor pressed the button. Pressing the button could still activate the Pit if the dial swung to the left; if it swung to the right, the Tyre could also alternatively trigger a new mode called Rogue House Robot, which allows one House Robot to actively join the battle for ten seconds. The competitor closest to the House Robot in question is attacked first, but if the competing robot escapes, the House Robot will attack one of the other three competitors if the fight is a Group Battle, and the other competitor robot in a Head-to-Head battle. The time limit for the Rogue House Robot attack is specified by a scattering of spotlights that scan around the arena floor, with the dial above the Arena Tyre resetting to the centre after the Rogue House Robot attack finishes. Additionally, if the Pit was activated, it was shown in one battle to automatically raise after a set time period, with the dial again resetting to the centre. Each competing robot is allowed to activate the Arena Tyre into Pit mode or Rogue House Robot mode once in every battle.

For Series 10, a third Arena Tyre mode, Fog of War, is due to be introduced, which will result in dense fog filling the arena for ten seconds. This mode was originally planned to be introduced in Series 9, but was not implemented for that series.

The dial, referred to in the show as the Dial Of Doom or the Doom Dial, first appeared in the Battle of the Stars Christmas specials, although it remained unused throughout the specials.

Floor Flipper
The Floor Flipper is a powerful pneumatic flipper built into the floor, which could toss robots across the arena if they were positioned on it. In the original series, it was used as a form of punishment when a robot had become immobilised, and was one of the most popular. This hazard was introduced in Series 3, where it conspicuously looked like a panel in the arena floor, the only form of identification being the black and yellow hazard tape around its borders. In Series 4, the Flipper was redesigned to resemble the pit, painted in black and yellow hazard stripes with a red border, an appearance which it maintained until the end of the original series' run. From Extreme 1 onwards, the Floor Flipper's pneumatics were significantly upgraded over time, allowing it to toss heavyweight robots several metres into the air and eventually to the other side of the arena. The Floor Flipper was first used to toss the defeated Behemoth in the final of Series 3, Heat B, while the last time it was used in the original series was on Crushtacean in The Third World Championship (the final time it was actually used was on Behemoth in the Series 7 House Robot Rebellion, the last fight to be filmed in the original show's run). The Floor Flipper was also occasionally known as The Evil Ejector on occasions, chiefly in the Fourth Wars Celebrity Special. In the original series, the Floor Flipper was usually only used to flip immobilised robots, but there were some notable exceptions:
 * In the House Robot Rebellions of Extreme 1 and Series 7, it threw Plunderbird 5 and Behemoth across the arena respectively when each competitor simply drove over it.
 * Ripper was also thrown in a similar fashion after attacking the House Robots in Series 7.
 * In Series 7 Heat J, 8645T 2 was righted after being flipped by Thermidor 2 and counted out, before driving straight across the arena where the flipper activated and threw 8645T 2 halfway across the arena.
 * In the first eliminator of the Series 7 All-Stars, the Floor Flipper was fired in an attempt to flip the still-active competitors in response to their attack on the House Robots.

On a number of occasions, the Floor Flipper showed its immense power by hurling featherweights out of the arena - Rampage 2 and G2 both suffered this fate in Series 7. It also twice managed to flip robots into the pit, which happened to the featherweight Cygnus in Series 7 (who was on the floor flipper at the same time as G2) and the heavyweight Fluffy after being eliminated from its Extreme 1 Mayhem battle. In rare circumstances, the Floor Flipper failed to throw competitor robots over completely; either due to poor positioning or too much weight being placed on the flipper. In Series 7, NEATer Machine was only placed halfway over the panel, resulting in it being launched straight up into the air and landing partly inside the raised flipper. In Series 5, the walker Black Widow was placed in a similar position, and balanced on the edge of the floor flipper when it fired. After being fully pushed onto the panel however, Black Widow was eventually thrown over.

As the mechanism of the Series 5-7 flipper was exposed when opened, it was possible for robots to get wedged in between the closing panel and the mechanism inside if they strayed too close. This happened to Atomic in its Extreme 1 Mayhem after the flipper flipped Mousetrap over, while in the Extreme 1 Antweight Melee, Anty B fell inside the flipper mechanism after it fired, eliminating it instantly. The Floor Flipper was one of the four main hazards which returned as part of the new arena (along with the Pit, floor spikes and Flame Pit). It is now positioned diagonally to the rest of the arena, firing in the direction of the pit, and the flipper's pneumatic mechanism is now sealed. The most notable difference with the Floor Flipper is that it now fires on mobile competitors during battles whenever they drive or are pushed over it, instead of being solely used to throw defeated robots after they have been deemed immobilised. As with the Pit, Flame Pit and CPZs, a camera has been positioned underneath the transparent portion of the Floor Flipper.

While the Floor Flipper mechanism has been sealed for Series 8-10, it is still capable of trapping robots underneath it as it returns to its 'closed' position. This occurred with Nuts during its Head-to-Head fight against Behemoth in Series 8: the flipper fired, missing both robots, but its outer edges caught one of Nuts' chain flails as it closed, briefly holding Nuts in place before releasing it. The flipper would later trap the entirety of Cherub under it during its fight with Behemoth in Series 9, causing the battle to be restarted.

Flame Pit
The Flame Pit was introduced in Series 2, located on the right-hand side of the arena. It consisted of a large grille located on the right-hand side of the arena, roughly about the same size as the Pit, which fired several jets of flame whenever a robot crossed over it. The Flame Pit was often used to damage the electrical circuits of any robot that drove or was pushed onto it, or to set fire to flammable armour, fuels and fluids - notable cases of the latter include Technophobic's demise in Series 3 and the numerous times where Diotoir's polka-dot fur was set alight after being flipped or pushed onto it. The Flame Pit let out considerably more flames than the floor and wall-mounted flame jets (see below), and was one of the more visually recognisable hazards. It was also known as the Flames of Fury in the Series 4 Celebrity Special, although this was not used outside the special. For Nickelodeon Robot Wars and some battles in Extreme Warriors, the Flame Pit was disabled and modified to fire jets of CO2 instead, although clips of it spouting flames were still shown during the House Robot introductions for the Nickelodeon series. In Series 8-10, the Flame Pit was made much larger than before, and is now located on the left-hand side of the arena right in front of the Pit. It was never referred to by name during these series and was simply described as Fire, although the official website still referred to the Flame Pit by its name.

Flame Jets
A variety of flame jets were seen in later series, usually smaller than the Flame Pit and covering a smaller surface area. However, they still served the same function, in that they could cause damage to robots' internals and set flammable materials on fire whenever a competitor was close to them.
 * The first type were the wall-mounted jets, which in Series 3 and 4 acted as flamethrowers and fired whenever a competitor strayed too close to the front wall near one of the CPZs. They merely served as an atmospheric hazard, although they were capable of setting robots like Steg 2 and S.M.I.D.S.Y. alight on various occasions. From Series 5-7, these flame jets were repurposed as a purely atmospheric feature, shooting flames vertically on either side of the House Robot Entrance during the course of battles, but not directly interacting with the arena.
 * The second and more common type were the floor-mounted flame jets, first seen in Series 4. They were similar to the Flame Pit and CO2 jets in that they fired jets of flame from beneath the floor. They were equally potent in causing damage to robots' internals, such as immobilising Terror-Bull in Series 4 after it chose to drive on one of them to set its tail alight during its battle against Raizer Blade.

Flame jets returned to the arena for the reboot, and like in Series 5-7 were located outside the main arena, lining the entry gate where the House Robots drove in to the arena.

Arena Spikes
Pneumatic Arena Spikes were prevalent in the early series and Series 8-10, and would fire up from the arena floor individually or in groups of five. In Series 1-2, they would raise slowly in order to lift robots up, dislodge tracks/drive chains or impede their progress in the Gauntlet. However, in Series 3, the spikes were upgraded and fired noticeably faster than before, often carrying enough power to thrust robots off the ground. This often knocked them off balance or flipped them over completely, leading to many sudden defeats for robots such as Behemoth, Pitbull and Thing 2, who dominated their respective battles before getting flipped over by a spike. As a result of their interference, the floor spikes were removed for Series 4. Despite the controversy surrounding the spikes, they returned as part of the Series 8-10 arena. However, the new spikes are now independently operated, and grouped in a set of five marked in a red square, making them much more recognisable for roboteers and spectators. Whilst still powerful enough to lift robots off the ground, and travelling further up than before, the Series 8 spikes are significantly slower than their controversial predecessors, theoretically tackling their main issue. When one or more of the spikes are raised with a competitor stranded on them, a set of sparks is fired from a hole near the centre spike. In Series 9-10, the arena spikes are no longer fired individually, and move much faster than in Series 8. They are capable of trapping smaller robots in place when they drive over them, interfering with their manoeuvrability, as what happened to Dee during its Battle of the Stars fight against Soldier Ant. Additionally, their faster movement enables them to flip competitors over as in Series 3, with Aftershock notably becoming flipped over by one during its battles against Terrorhurtz and Ironside3 respectively.

Corner Patrol Zones
The Corner Patrol Zones (often abbreviated to CPZs) are a set of four designated areas around the corners of the arena where the House Robots are stationed throughout every battle. If a competing robot enters one of these zones, the House Robot inside the CPZ is allowed to attack them at their own will, causing significant damage or potential immobilisation in the process. If a robot became immobilised in the original series, however, the House Robots were permitted to leave their CPZs and cause further punishment, often disposing of competitors by taking them to other hazards such as the Floor Flipper and the Pit. From Extreme 1 onwards, the House Robots were not allowed to leave their CPZs and attack mobile competitors outside them, otherwise they would receive a yellow or red card from Refbot depending on how frequently they breached this rule or how severe their attacks were.

In Series 1, the CPZs featured spiked pyramids and side bars (see below) as additional hazards, and were outlined in yellow and black hazard tape. From Series 3-7, they were identified by large yellow and black chevron stripes, accompanied by a red outline from Series 4 onwards. In Series 8-10, these markings were replaced with a simple black outline similar to those used for the other arena hazards. The CPZs appeared in every series apart from The Second Wars. In Series 1, the original four House Robots - Shunt, Matilda, Sergeant Bash and Dead Metal all had their own CPZs and appeared in every battle except for the Grand Final. In Series 3 and 4, the House Robots appeared in a rotation system between all five machines, with Sir Killalot appearing in every battle for Series 4. Notably, only two House Robots were present in the arena during battles in Series 4 that featured more than three competitor robots, such as the Tag Team Terror and the first three rounds of the Northern and Southern Annihilators. From the first series of Robot Wars Extreme to Series 7, only two House Robots were allowed in the arena at any one time (the House Robot Rebellions being a notable exception), and were selected as part of a rotation system between all machines. For Series 8-10, only one House Robot was seen in the arena in the first-round battles, with two being used for all subsequent rounds including the Group Battles for the Grand Final. Some notable exceptions did occur, however; for Robot Wars: Battle of the Stars, only one House Robot was present in most battles, except for the Episode 2 final. In Heat 5 of Series 9, Sir Killalot was the only House Robot present in the Head-to-Head battle between Apollo and Carbide.

In Series 2, the CPZs were temporarily replaced with the Perimeter Patrol Zone (see section below).

Entering a CPZ would cost points for 'control' if the match went to a judges' decision, but a robot would gain points for 'style' if it fought back against the House Robot occupying the CPZ. Competitors would also gain points for aggression for shoving opponents into a CPZ.

Perimeter Patrol Zone
For Series 2, the CPZs were replaced by the Perimeter Patrol Zone (PPZ), a marked area around the arena's circumference where the House Robots were free to attack any competitors that had strayed into it. From Heats A to F, the PPZ was marked in red and black stripes, before changing to black with diagonal yellow stripes from Heat G onwards. Four of the House Robots would be situated around the PPZ during each Arena battle, with all five appearing in the Grand Final battles alongside the Sentinel. The PPZ only appeared in this series, before the producers opted to revert back to the CPZs for the Third Wars onwards.

The Drop Zone
The Drop Zone was a black square with a yellow cross located opposite the Pit. Here, immobilised competitors would be pushed onto the square after being counted out by Refbot, and have heavy objects such as television sets, ocean buoys, bowling balls, refrigerators and washing machines dropped onto them from above.

The hazard was first introduced in the second season of Extreme Warriors and made its UK debut in Series 6, although the Drop Zone square previously appeared in Extreme 1 and Series 5 without serving any clear purpose at the time. The Drop Zone was originally intended to be activated by a button that competitors or House Robots could press (similar to the Pit and Disc of Doom buttons), but this idea was not implemented.The first robot to have an item dropped on it was Unibite 2.0 in Heat C of Extreme Warriors Season 2, while the first UK victim was Robochicken in Series 6, Heat B. The last competitor to have an object dropped from the Drop Zone was Hard in the first round of the Third World Championship, broadcast as part of Series 7. The Drop Zone was not featured as part of the current arena, and as such has effectively been retired.

In the first round of the Series 7 All-Stars Tournament, a washing machine was dropped in an attempt to stop the competitor robots following their attack on the House Robots, but missed.

Floor Spinner / Disc of Doom
The Floor Spinner, also known as the Disc of Doom, was used between Series 6 and Extreme 2. It was located near the centre of the arena, and consisted of a circular spinning panel built into the arena floor and painted to resemble a gear, which was intended to fling robots across the arena if they drove over it, interfering with their manoeuvrability. Like the Pit, the Floor Spinner was activated by a button positioned between two angle grinders on one of the side walls, which originally took the form of a yellow metal bumper similar to that of the Series 6 pit release button. However, for Extreme 2, this was changed to a yellow tyre identical in design to the Extreme 2/Series 7 pit release button. Known as the Disc of Doom, the hazard first appeared in the second season of Extreme Warriors and Nickelodeon Robot Wars, sporting a spiral pattern rather than the later gear design, and originally fitted with teeth built into it in order to snag competitors as they drove over it and cause damage to their wheels/tracks and chassis. However, this resulted in too many robots either getting stuck on the disc, such as Dragbot and Ninjitsu, or bumping into the teeth while attempting to drive over it. As a result, the teeth were removed for Series 6 and all the hazard's subsequent appearances thereafter. Even so, it was still possible for robots with low wedges, such as Firestorm 4 and Dantomkia, to accidentally get wedged underneath the Floor Spinner from time to time, posing another problem with the hazard. The Floor Spinner / Disc of Doom rarely proved effective in practice, and was removed at the end of Extreme 2.

Angle Grinders
The Angle Grinders were introduced in the first series of Robot Wars Extreme as a replacement for the circular saws from Series 2-4 and the static wall spikes from Series 4. Several of these lined the arena wall, contained in metal units labelled "DISC" on top, with the intention of cutting into other robots upon contact. However, they rarely saw any practical use, with the most significant damage being caused in the Extreme 1 All-Stars, when Pussycat had one of its wheels torn off by an angle grinder during its fight with Tornado.

They would sometimes get in the way of an attempted out of the arena flip, and as proved by robots such as Dantomkia and Micro-Mute, it was possible to easily become wedged underneath them. An angle grinder was also damaged in the Series 7 Semi-Final battle between Storm 2 and The Grim Reaper, after a slam from Storm 2 knocked the top panel off of one.

CO2 Jets/Steam Vents
Featured in Series 4-7, these small jets spouted CO2 upwards from the arena floor, close to the CPZs. While primarily atmospheric in nature, these jets also served as makeshift extinguishers for robots that had caught fire (e.g. Cyclone in the US Season 2 Annihilator), and could also obscure the view of roboteers, affecting their robots' control. To a lesser extent, they also caused problems for robots with holes in the bottom of their chassis, as the CO2 could seep in and freeze their electronics or internal combustion engines. This notably happened to Tetanus in Series 5 and Snake Bite in the European Championship, when they became immobilised after driving over a CO2 jet. They were also used for comedic effect, such as the moment when a CO2 jet blew one of Ruf Ruf Dougal's ears off in its Series 5 battle against Gemini.

Early / Other Hazards
Other notable hazards from the original series included:
 * Hanging Maces that swung in various places across the arena. They were also referred to as Swinging Pendulums, and were initially round and fairly small in Series 1, but were redesigned to become much larger and more cube-shaped in Series 2. Typically, they were more atmospheric than damaging and were removed ahead of Series 3.
 * Arena Side Bars running along the side walls, which were intended to lift robots off the ground and leave them stranded when they drove or were pushed onto them. They were best known for immobilising robots such as Mortis, Recyclopse, Torque of the Devil and REALI-T throughout Series 1, and were removed before Series 2.
 * Spiked Pyramids which usually lined the walls and were intended to act as an additional obstacle in the Gauntlet and CPZs/PPZ. Like the maces/pendulums, they served a primarily atmospheric purpose, and were removed before Series 3.
 * Sets of below floor-level Grilles (also called Grids), which could trap and immobilise robots that drove or were pushed over them. These were only seen in Series 1 and are generally considered to be the predecessors of the Pit of Oblivion, serving purpose in immobilising robots like Wedgehog, Plunderbird 1, Full Metal Anorak, and even Shunt throughout the course of the series.
 * Circular Saws (also referred to as grinders) which lined the arena corners in Series 2 and the walls in Series 3-4. These saws were fully exposed, unlike the later Angle Grinders, and were intended to create sparks and cause damage to competitors upon contact. They effectively served as predecessors to the Angle Grinders seen in later series, before being supplemented by static spikes for Series 4 and replaced by the former in Extreme 1/Series 5.
 * Static Wall Spikes, which lined the arena wall in Series 4 only. Large and coloured yellow, their most famous use was in Heat F, when Tornado impaled one of the Gemini twins onto a spike, effectively eliminating the clusterbot. The spikes were subsequently replaced by the Angle Grinders from Extreme 1 to Series 7.
 * Although they were never mentioned onscreen, a set of retractable spears also appeared in Series 4 only, located on the lower wall. They were long pneumatic spikes with large red tips that extended through the wall whenever competitors were nearby, and were seen to push robots away at various points throughout that series. Though largely inconspicuous, they were distinguished by a distinctive hissing sound that could be heard whenever they fired.