Robot combat
Robot combat is a mode of robot competition in which custom-built machines fight using various methods to incapacitate each other. The machines have generally been remote-controlled vehicles rather than autonomous robots. Robot combat competitions have been made into television series, including "Robot Wars" in the UK and "Battlebots" in the US. These shows were originally broadcast in the late 1990s to early 2000s and experienced revivals in the mid-2010s. As well as televised competitions, smaller robot combat events are staged for live audiences such as those organized by the Robot Fighting League. Robot builders are generally  hobbyists and the complexity and cost of their machines can vary substantially. Robot combat uses weight classes, with the heaviest robots able to exert more power and destructive capabilities. The rules of competitions are designed for the safety of the builders, operators, and spectators while also providing for an entertaining spectacle. Robot combat arenas are generally surrounded by a bulletproof screen. Competitor robots come in a variety of designs, with different strategies for winning fights. Robot designs typically incorporate weapons for attacking opponents, such as axes, hammers, flippers, and spinning devices. Rules almost always prohibit gun-like weapons as well  as other strategies not conducive to the safety and enjoyment of participants and spectators. History. Among the oldest robotic combat competitions extant in the United States are the "Critter Crunch" (founded about 1987) in Denver and "Robot Battles" (founded in 1991) based in the southeastern U.S. Both events are run by members of the "Denver Mad Scientists Society". Rules. Robot combat involves remotely controlled robots fighting in a purpose-built arena. A robot loses when it is immobilized, which may be due to damage inflicted from the other robot, being pushed into a position where it cannot drive (though  indefinite holds or pins are typically not permitted), or being removed from the arena. Fights typically have a time limit, after which, if no robot is victorious, a judge or judges evaluates the performances to decide upon a winner. Weight classes. Similar to human combat sports, robot combat is conducted in weight classes though with maximum limits even in the heaviest class. Heavier robots are able to exert more power and have stronger armor and are generally more difficult and expensive to build. Class definitions vary between competitions. The below table shows classifications for two organizations: the UK-based Fighting  Robots Association (FRA) and the North American SPARC. Most televised events are of heavyweights. Currently "Battlebots" has a weight limit of . To encourage diversity of design, rules often give an extra weight allotment for robots that can walk rather than roll on wheels. Safety precautions. Given the violent nature of robot fighting, safety is a central factor in the design of the venue, which is generally a sturdy arena, usually constructed of steel, wood, and bulletproof clear Lexan plastic. The smaller, lighter classes compete in smaller arenas than the heavyweights. Competition rules set limits on construction features that are too  dangerous or which could lead to uninteresting contests. Strict limits are placed on materials and pressures used in pneumatic or hydraulic actuators, and fail-safe systems are required for electronic control circuits. Generally off-limits for use as weapons are nets, liquids, deliberate radio jamming, high-voltage electric discharge, untethered projectiles, and usually fire. Robot fighting associations. The sport has no overall governing body, though some regional associations oversee several events in managerial or advisory capacities with published rulesets. These include: The major televised competitions have operated outside of these associations. Combat robot weaponry and design. An effective combat robot  must have some method of damaging or controlling the actions of its opponent while at the same time protecting itself from aggression. The tactics employed by combat robot operators and the robot designs which support those tactics are numerous. Although some robots have multiple weapons, the more successful competitors concentrate on a single form of attack. This is a list of most of the basic types of weapons. Most robot weaponry falls into one of the following categories: Many modern rulesets, such as the rebooted versions of "BattleBots" and "Robot Wars", require robots to have an active weapon in order  to improve the visual spectacle, thus eliminating certain designs such as torque-reaction axlebots and thwackbots, and requiring other designs such as wedges and rammers to incorporate some other kind of weapon. Interchangeable weaponry. It is increasingly common for robots to have interchangeable weaponry or other modular components, allowing them to adapt to a wide range of opponents and increasing their versatility; such robots are often referred to as "Swiss army bots", in reference to Swiss army knives. Arguably the earliest example was Robot Wars Series 1 contestant "Plunderbird", which could change between a pneumatic spike and a circular saw  on an extendable arm. Successful Swiss army bots include Robot Wars Series 6 champion "Tornado", BattleBots 2016 runner-up "Bombshell", and top-ranked US Beetleweight "Silent Spring". Sometimes, robots that were not originally Swiss army bots have had their weapons changed or altered on the fly, typically due to malfunctions. In BattleBots 2015, "Ghost Raptor"'s spinning bar weapon broke in its first fight; builder Chuck Pitzer then improvised new weapons for each following fight, including a "De-Icer" arm attachment which it used to unbalance and defeat bar spinner "Icewave" in the quarter-finals. Prohibited weaponry. Since the first  robot combat competitions, some types of weapons have been prohibited either because they violated the spirit of the competition or they could not be safely used. Prohibited weapons have generally included: Individual competitions have made exceptions to the above list. Notably, the Robotica competitions allowed flame weapons and the release of limited quantities of liquids on a case-by-case basis. The modern series of "BattleBots" also permits the use of flamethrowers and, as of 2016, untethered projectiles, provided that the latter are merely for show. Competitions may also restrict or ban certain otherwise legal weapons, such as banning spinners  and other high-power weapons at events where the arena is not able to contain these weapons. A well-known example of this is the Sportsman ruleset. Arena hazards have also been granted exceptions to the list of prohibited weapons. "Robot Wars" in particular used flame devices both in the stationary hazards and on one of the roaming "House Robots". Unusual weaponry. A very wide variety of unusual weapons and special design approaches have been tried with varying success and several types of weapons would have been tried had they not been prohibited. Unusual propulsion. The great majority of combat  robots roll on wheels, which are very effective on the smooth surfaces used for typical robot combat competition. Other propulsion strategies do pop-up with some frequency. Robot-sumo. Robot-sumo is a related sport where robots try to shove each other out of a ring rather than destroy or disable each other. Unlike remote-controlled combat robots, machines in these competitions are often automated. External links. North America South America Europe Australia