---
title: "Robot combat"
chunk: 10/11
source: "https://en.wikipedia.org/wiki/Robot_combat"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:20:55.912995+00:00"
instance: "kb-cron"
---

Tank treads – Numerous combat robots have used treads or belts in place of wheels in an attempt to gain additional traction. Treads are generally heavier and more vulnerable to damage than a wheeled system and offer no particular traction advantage on the types of surfaces common in robot combat. Most uses of treads are for their striking appearance. The Robot Wars competitors Track-tion, 101 and Mortis along with the BattleBots super heavyweight Ronin used treads. Biteforce, the winner of the 2015 Battlebots Competitions, originally used magnets embedded in its treads in an attempt to gain extra downforce without extra weight. Current users of treads include 2022–2023 NHRL champion and BattleBots contestant Emulsifier and BattleBots fan-favorite Rusty. Walking – The spectacle of a multi-legged robot walking across the arena into combat is a big audience favorite. Robot combat rules typically have given walking robots an additional weight allowance to offset their slower speed, the complexity of the mechanism, and to encourage their construction. What the event organizers had in mind was something like the spider-legged robot Mechadon, but what most often was produced were simple rule-shaving propulsion systems that attempted to save as much of the extra weight allowance as possible for additional weaponry. Attempts at more restrictive definitions of "Walking" have effectively eliminated walking robots from competition. BattleBots heavyweight champion Son of Whyachi used a controversial cam-driven "Shufflebot" propulsion system, which was promptly declared ineligible for additional weight allowance at subsequent competitions. The most recent true walker to appear on BattleBots was the 2020 iteration of Chomp, a 500 pounds (230 kg) robot that moved using six legs and was equipped with a hammer and flamethrower system on a turret. The enormous walker still retained similar autonomous technology as its predecessor, but it was extremely slow and had a below-average win record. Gyroscopic precession – Used in the Antweight robot Gyrobot, as well as the Battlebots competitor Wrecks, this system uses a gyroscope and stationary feet that lift as the entire robot rotates due to gyroscopic precession when the gyroscope is tilted by a servo motor. This design can use the gyroscope as a spinning weapon (horizontal or vertical) which allows for efficient double-usage of the gyroscope mass. Although Gyrobot and Wrecks appear to be walking as it translates across the arena, they are not classified as walking robots under current rules. This unusual drive train produces strange and often unpredictable movements, though has shown to be successful in combat. Torque reaction - Torque reaction has seen use in lower weight classes for both weaponry and locomotion. A famous example of this is in the beetleweight Droopy, which alters the speed of its two angled horizontal spinners to waddle forwards and turn via self-induced gyroscopic precession and the conservation of angular momentum. Full-bodied beetleweight drum spinner robots Noob Tube and Bee Roll use two powerful motors to simultaneously drive their wheels and weapon as a result of this principle. Suction fan – Several competitors experimented with the use of fans to evacuate air from a low-clearance shell to suck the robot down onto the arena surface and add traction. Robotica competitor Armorgeddon used a suction fan to increase traction and pushing power, and Robot Wars and Battlebots competitor Killerhurtz experimented with use of a suction fan to counter the forces from its hammer/axe weapon, a system that was demonstrated as giving the robot the ability to climb walls but was never utilised in combat. Similar designs have appeared in robot-sumo competitions where traction is a key factor. Magnetic Wheels – Another approach to gaining traction and stability involves the use of rare-earth magnets, either ring-shaped as wheels or simply attached to the robot's base. This is, naturally, only effective in arenas that have magnetic metal surfaces. Due to the expense of large ring magnets, this trick has been used almost exclusively in three-pound and under "insect class" robots, although a lightweight battlebot General Gau tried implementing them. A multibot named Hammer and Anvil would later use magnets in the lightweight category, with some success. Heavyweight Robotica competitor Hot Wheels attempted to use a large chassis-mounted magnet to gain traction and apparent weight, and Beta unsuccessfully attempted to use an electromagnet to counter the reaction forces of its massive hammer weapon at the BattleBots competition. This however was removed for future competitions as the power of the magnets rendered the robot unable to move. Mecanum wheels – Together with a specialized motor control system, mecanum wheels allow controlled motion in any direction without turning, as demonstrated by Alcoholic Stepfather in a 2004 match, and by the hammer-wielding Battlebots competitor Shatter! in 2019. Flying – The 1995 US Robot Wars event had a flying competitor: S.P.S. #2 was a lighter-than-air craft buoyed by three weather balloons and propelled by small electric fans. It attempted to drop a net on the opponent. Nearly invulnerable to attack, it won the first match against Orb of Doom (see reference below), but ventured too close to the arena floor in the second match and was dragged down and "popped". Starting in 2016, BattleBots permitted the use of drones as "nuisance bots"; these typically proved hard to control, and one was memorably swatted out of the air by a rake that competitor HyperShock had attached to its lifting forks. These drones are usually armed with flamethrowers, but there is no evidence that these have ever had an effect on the opponent, and as of World Championship VII, only one drone, named Spitfire, remains, and it is used very infrequently. Rolling sphere – The aforementioned Orb of Doom was a featherweight competitor at the 1995 US Robot Wars. It consisted of a lightweight, rigid shell made of carbon fiber-kevlar cloth and polyester resin, applied over a foam core pattern. Inside was an offset-weight mechanism made from a battery-powered electric drill. A similar-looking robot named Psychosprout appeared in the UK Robot Wars. Rolling tube – Snake competed at Battlebots and the US Robot Wars using a series of actuators to bend its triangular cross-section tubular body to roll, writhe, and slither across the arena. Shuffling – refers to the movement of robots that are propelled by a cam-driven system. See Walking
Brush Drive – Similar to Gyroscopic precession, brush drive uses brushes affixed to the bottom of the robot, akin to non-combat bristlebots. These work in tandem with a pair of vertical spinning weapons to make the robot slide across the arena. This form of locomotion has been utilized by RoboGames 2017 competitor Clean Sweeper. Alternatively, brush drive has been shown to work with slightly-offset horizontal spinners, as the infamous NHRL featherweight Depth Charge could vibrate across the arena via two massive steel discs that were powerful enough to breach the arena's inner layer. Magnets and Rapid Deceleration – While it has never been done, an entrant to Battlebots' seventh season, titled Bad Penny, had planned on using a magnetic system combined with a braking system to move their robot around the arena. Six magnets would pull down on the floor with over 2000 pounds (~909 kilograms) of force.