Robot Wars Wiki

"A clusterbot is a machine that's made of two or more parts, which gives our opponent not just one problem to deal with, but multiple issues about how you fight something that's in two places at once."
— Alex Botwright explains the logic behind Crackers 'n' Smash

Clusterbots, first introduced in the fourth series of Robot Wars, are a special type of competitor robot which consist of two or more robots rather than one. They would enter the arena together as one machine, before separating and fighting as separate robots when the battle began.

Clusterbots were rather uncommon in Robot Wars, with only eight entries of the conventional variety having competed in any domestic series across both of the show's runs. The most successful of these are joint-pioneer and Series 4 Heat-Finalist Gemini, Dutch Series 2 Heat-Finalist √3² and Extreme 2 Middleweight Finalist Typhoon Twins. Another clusterbot, Share + Destroy, was also planned to enter Series 4, but failed to qualify.


Once one half of Gemini was immobilised on an arena spike, both halves were eliminated as one machine

The rules governed for clusterbots state that while there are no limits for the number of robots they can be made out of, the combined weight of each robot must be within the given weight limit for each category (for example, 79.4kg, 100kg or 110kg for heavyweights). Although not mentioned in the build rules themselves, the number of clusterbot segments allowed in the arena at once is also limited by the number of team members available to drive them. As of Series 10, the maximum is four parts for a team consisting of four members, with the option to use any extra segments interchangeably. In the original series, clusterbots were also required to be attached to each other before the battle started, although this rule was not applied to the reboot.

Clusterbots also had to face additional rules in terms of immobilisation. The original rule stated that if one of the robots was rendered immobile, then the entire robot would be deemed immobile and therefore eliminated. As a result, robots fighting them would often concentrate on defeating one half of the robot. A key example is Tornado during its Series 4 Heat Final against Gemini, which focused on impaling one half on an arena spike in order to eliminate it.

"... and I think half [of Gemini] is impaled on the arena wall. Can they get away there? If they're immobilised for longer than 30 seconds, that's it..."
Jonathan Pearce, stressing the original clusterbot immobilisation rule as Tornado impales one of the Gemini twins on a wall spike

Despite Matilda hurling S.O.Xbot out of the arena, later changes to immobilisation rules enabled √3² to keep fighting and win against Pika 3 with its two remaining segments

As a Middleweight clusterbot, Typhoon Twins were able to continue fighting despite one half falling into the pit

After Series 4, the rules were revised so that 50% of the robot in terms of weight had to be immobilised in order for the clusterbot to be eliminated. Whilst this largely did not affect most clusterbots at the time, as they generally consisted of two robots of equal weight, it did affect the Dutch three-part clusterbot √3². During its Dutch Series 2 run, √3² was still able to win its Heat Semi-Final against Pika 3 on a Judges' decision even after Matilda threw one of its segments (S.O.Xbot) out of the arena. Had the House Robot's attack occurred in Series 4 or earlier, it would have counted as an immobilisation.

Although consistently applied in the main heavyweight competitions, the above rule did not appear to be strictly enforced in the lower weight classes. This was evident in each series of Robot Wars Extreme, in which the antweight Legion and middleweight Typhoon Twins both continued to fight even after one half had become immobilised or pitted.

For Series 9-10, the rule was changed so that 60% of a robot must be defeated for the whole robot to be considered immobile. Competitor robot Crackers 'n' Smash capitalised on this by having each half of the robot weigh 50kg and 60kg respectively - as neither part of the robot weighed more than 66kg, both halves of the robot would have needed to become immobilised before Crackers 'n' Smash as a whole could be deemed immobile. In the case of the four-part clusterbot The Swarm, three parts were required to be immobilised in order for it to be eliminated.

Prior to Series 4, clusterbots were not allowed to fight in melees due to potential radio interference issues.[1][2]


A similar concept to the clusterbot exists in the form of minibots. These involve small robots that competed alongside the main competitor, which were significantly lighter, and were neither required to be attached to the main competitor at the start of the battle nor to feature an active weapon.

Minibots were typically used to distract and disrupt an opponent's movements, interfering with their attacks, but were considerably more fragile than standard clusterbots due to their smaller size. As a result, minibots were largely considered to be sacrificial, and would not usually fight again if they became severely damaged in battle.

The Hatchling

The first robot to use a minibot, although the concept was not named as such at the time, was Psycho Chicken in Robot Wars: Extreme Warriors, with its egg-shaped minibot, 'Scramble'. However, the concept would not be explored again until the eighth UK series, with two minibots appearing as part of Nuts, and one ('The Hatchling') accompanying Terror Turtle. By far the most successful robot with minibots is Nuts 2, which finished joint-third overall in Series 10 - the best performance of any clusterbot in Robot Wars history.

Advantages and Disadvantages[]


All three parts of √3² try to push ODT-Zero into the pit

In an attempt to free its twin from Razer's grip, one half of Gemini flipped both robots simultaneously

Nuts 2's minibots attempt to disrupt Androne 4000's movements

Crackers wedges itself underneath Apollo

The concept of The Swarm enabled it to swap at least one of its individual segments in between battles; both versions of Skye would be used for its Series 10 battle against Sabretooth

  • Through comprising of two or more robots, clusterbots are more difficult for opponents to defeat quickly, since they require one or all parts to become immobilised before they can be eliminated.
  • A clusterbot can allow for an effective attack synergy between individual segments; it was not uncommon for all parts of a clusterbot to block and surround opponents when fighting simultaneously, overwhelming or otherwise preventing them from attacking effectively. This tactic was demonstrated by Gemini, √3², Crackers 'n' Smash and The Swarm during their respective appearances.
    • An alternative tactic can allow clusterbots to separate and attack two or more opponents at once in Group Battles; both Crackers 'n' Smash and The Swarm demonstrated this in their respective series debuts.
  • Additionally, if one part of a clusterbot is attacking or preparing to attack an opponent, the others can be used to activate arena hazards very quickly. Notably, one of Nuts 2's minibots succeeded in eliminating Behemoth from their Series 10 Grand Final Group Battle by pressing the Arena Tyre and activating the pit, just as the latter was sent recoiling towards it by Carbide. The same tactic also allowed Nuts 2 itself to avoid its opponents while they attacked each other, giving it enough time to spin its flails up and break Carbide's weapon chain.
    • In some cases, individual clusterbot segments can use certain arena hazards or their own weapons to help other segments in battle. A notable example occurred during The Swarm's Series 10 fight against Sabretooth, where the invertible Skye pushed the inverted Rubber Duck onto the Floor Flipper, re-righting the latter in the process.
  • If one part of a clusterbot is attacked, the other parts can assist it by targeting opponents which initiated the attack. This is best demonstrated in Gemini's All-Stars battle against Razer in Extreme 1, where one half of Gemini lifted and flipped Razer over in a successful attempt to free its twin from the latter's grasp.
  • Depending on their design, smaller-sized clusterbots - especially minibots - can prove highly effective in disrupting an opponent's movements, as their size can enable them to block or even get underneath them. Nuts' wedge-shaped minibots, for example, succeeded in getting themselves underneath Behemoth, Terrorhurtz, Androne 4000, Concussion and Carbide on various occasions. In most cases, these attacks prevented their aforementioned opponents from driving properly and attacking the main robot. Meanwhile, Crackers got underneath and affected the movements of Carbide, Apollo and even Sir Killalot at various moments in Series 9-10.
  • For clusterbots consisting of more than four parts, it is possible to exchange different segments to suit different opponents and tactics, adding to their versatility. The Swarm was conceived as such that it could use four out of its five segments at once; for its battle against Sabretooth, the team were able to exchange Pinza for one version of Skye featuring anti-spinner defences.


Smash (top-left) is flung out of the arena by Big Nipper

The remains of Scramble, Psycho Chicken's minibot, after being destroyed by Propeller-Head

  • In order to keep within the given weight limits, each segment of a typical clusterbot was required to be significantly smaller and lighter than normal competitors in their respective weight classes. As a result, they were usually more susceptible to getting pushed around, flipped, or seriously damaged by opponents, as the various defeats of Gemini, Black and Blue, √3², Crackers 'n' Smash and The Swarm demonstrated.
    • Minibots were especially susceptible to these issues due to their significantly smaller size and usually lower build quality. Nuts' minibots in particular were both thrown by Behemoth and damaged by Carbide at various points during Series 8, while Scramble (Psycho Chicken) was so severely damaged by Propeller-Head in US Season 2 that it entered its next battle without any form of mobility.
  • Due to them comprising of two or more robots, clusterbots require significantly more time and effort to maintain in between battles than regular competitors, since the team has to repair all parts of the robot at once within the allotted timeframe. Additionally, they require at least two or more drivers, adding to the complexity of operating them in the arena.
"If both robots take a lot of damage, we don't have just one robot to repair, but two, which could potentially be twice the work."
— Alex Botwright

List of Clusterbots/Minibots[]

Robots are listed alphabetically. Clusterbots which are not heavyweight entries are listed with a green background. Minibots are listed with a blue background. Robots that fought in the US 1990s events are highlighted in purple.

Robot Series Appearances Notes Image
Black and Blue Series 7 A clusterbot built by Team MouseTrap. Both halves were equipped with 20kg, 6,000rpm spinning drums.
Coyote Series 10 Featured a weaponless minibot named Roadrunner in Series 10 only.
Team Coyote Series 10.jpg
Crackers 'n' Smash Series 9-10 Two similarly-sized box-shaped robots with completely different weapons. Crackers weighs 50kg and is equipped with interchangeable lifters (originally a front-hinged lifting arm), while Smash weighs 60kg and features a drum-like vertical spinner.
Crackers-and-smash 10.png
Expulsion Series 10 Featured a two-wheeled minibot, Detention, which competes alongside the Series 10 version of the main robot.
Team Expulsion Series 10.jpg
Gemini Series 4-5, Extreme 1 The first UK series clusterbot, and the most successful traditional heavyweight clusterbot. Only clusterbot to throw an opponent out of the arena. Won Best Design and Most Original Entry awards in Series 4, as well as the Series 4 Pinball Warrior Tournament. Each half equipped with a pneumatic flipping arm.
Gemini Side View S5.png
Grunt 1995 UK Open Competition Originally a clusterbot when it competed in the 1995 UK Open Competition. Later competed in Series 1 as a singular robot.
Legion Extreme 1 Only antweight clusterbot. Each half equipped with a flipping arm.
Legion together.jpg
Meggamouse Series 9 Included the main Meggamouse robot with a minibot Charles, shaped like a wedge of cheese.
Nuts Series 8-10 First clusterbot in the UK series to be made up of more than two robots. Comprised of one heavyweight robot (Nuts) plus two small wedge-shaped minibots. Returned for Series 9 as Nuts 2 with three redesigned minibots. In Series 10, one of the four minibots featured a 6hp drive system; only two of the four minibots were able to be used at once in the latter series due to Team Nuts consisting of three members. Finished joint-third in Series 10, the best-performing clusterbot of any kind in the main UK Championship.
Nuts 2 S10.jpg
Psycho Chicken US Season 2 The first competitor in any series to use a minibot, competing alongside an egg-shaped robot called Scramble.
Terror Turtle Series 8 Comprised of the primary heavyweight Terror Turtle, plus a 21.5kg minibot called The Hatchling which only appeared alongside Terror Turtle in Series 8.
Terror Turtle 2016.jpg
The Kegs Series 10 A pair of two similarly-designed middleweight robots made out of two halves of a beer keg. Each half is invertible and armed with a horizontal bar spinner.
The Swarm Series 10 Five parts, each with unique weapons - Rubber Duck (flipper), Blenda (invertible bar spinner), Pinza (horizontal pincers), Skye ('windmill' with tyre sections and Sit-and-spin capabilities) and an invertible fifth robot also named Skye with a ramming wedge and optional static scoop. Four of the five parts can be paired together at once, with the robots used depending on which opponents The Swarm faces.
Triple Redundancy 1996 Championship Three RC cars with rolls of tape as weapons. First three-part clusterbot to appear in any series and the first known clusterbot in general.
Triple redundancy.jpg
Typhoon Twins Extreme 2 Comprised of Extreme 2 Lightweight Champion Typhoon Thunder and a second identical robot Typhoon Lightning, both with 700rpm full-body spinners. Extreme 2 Middleweight Championship finalist.
Typhoon Twins.png
√3² Dutch Series 2 First three-part clusterbot to appear in any televised series and first clusterbot to feature non-identical designs for each robot. The wedge-shaped S.O.Xbot and box-shaped Elevation both featured flipping arms, while ODT-0.33 featured a simple wedge.