As with other robot combat competitions, Robot Wars competitor robots were split into several weight classes (also known as weight categories). Although the first series included robots from various weight classes, subsequent series generally only included heavyweight robots in the main competition, with robots from other weight classes generally competing in their own competitions. As Robot Wars was originally created in America, the weights were originally dictated in pounds, and converted to kilograms without rounding up. The original weight limits for each class were as follows:
- Featherweight: 11.4kg
- Lightweight: 22.7kg
- Middleweight: 45.4kg
- Heavyweight: 79.4kg
- Super Heavyweight: 154kg
Some competitors in Series 1-4 were given some leniency; it was not uncommon for heavyweights to weigh a few kilograms over their official weight limit in those series. Being classified as a heavyweight on the show, Series 1 competitor Barry also notably broke the limit by weighing 116.9kg, which would still render it a super heavyweight to this day.
The weight limits were increased from Extreme 1 onwards, and an antweight class was added. The new weight limits were as follows:
- Antweight: 150g
- Featherweight: 12kg
- Lightweight: 27kg
- Middleweight: 54kg
- Heavyweight: 100kg
- Super Heavyweight: 200kg
To encourage creativity, walkerbots were allowed to enter one weight class below their actual weight, or weigh up to 200kg in the heavyweight competition (160kg prior to the increased limits). Super heavyweight walkers received no weight bonus. A derivative of walkerbots, shufflebots, were originally classified as walkers, and given the same weight limit as the latter. This was until Series 6, where the maximum weight limit for shufflebots was reduced to 150kg; however, some shufflebots, notably later versions of Ansgar, were still built to the original 200kg limit.
The weight limit for standard robots was increased again in Series 8 of Robot Wars, which only featured the heavyweight class. The weight limits for walkerbots and shufflebots were also altered.[1]
- Heavyweight: 110kg
- Heavyweight walkerbot: 135kg
- Heavyweight shufflebot: 120kg
In Series 10, the weight limits for heavyweight walkerbots and shufflebots were both increased, to encourage more robots of their kind to be built for the rebooted series.[2]
- Heavyweight walkerbot: 145kg
- Heavyweight shufflebot: 125kg
Additionally, a featherweight class was proposed and announced as part of the initial application process for Series 10. However, due to scheduling issues, the category was subsequently postponed. The weight limits for the proposed featherweight category were as follows:
- Featherweight: 13.6kg
- Featherweight walkerbot: 17.6kg
- Featherweight shufflebot: 15.1kg
Champions
From Series 2 onwards, the main competition was intended solely for heavyweight competitors, which meant that robots from other weight classes had to enter their own separate competitions. Series 2 featured competitions for all the other weight classes (except the Antweight class, which was not introduced until Extreme 1), but these competitions became less frequent in subsequent series and were mainly restricted to special events shown as part of Robot Wars Extreme and Series 7.
Antweight
- Main article: Antweight Championship
- Extreme Series 1: Combat Ant
- Extreme Series 2: Anty B
Featherweight
- Main article: Featherweight Championship
- Series 2: Demolisher
- Series 3: Event cancelled
- Extreme Series 1: Beef-Cake
- Extreme Series 2: Argh!
- Series 7: DTK
Lightweight
- Main article: Lightweight Championship
- Series 2: Slippery Strana
- Series 3: Event cancelled
- Extreme Series 1: Event cancelled
- Extreme Series 2: Typhoon Thunder
Middleweight
- Main article: Middleweight Championship
- Series 2: Hard Cheese
- Series 3: Event cancelled
- Extreme Series 1: Typhoon
- Extreme Series 2: Typhoon
- Series 7: Typhoon
Heavyweight
- Main article: UK Championship
- Series 1: Roadblock
- Series 2: Panic Attack
- Series 3: Chaos 2
- Series 4: Chaos 2
- Series 5: Razer
- Series 6: Tornado
- Series 7: Typhoon 2
- Series 8: Apollo
- Series 9: Carbide
- Series 10: Eruption
Super Heavyweight
- Main article: Super Heavyweight Championship
- Series 2: Kick Robut
- Series 3: Event cancelled