Interchangeable Weaponry

"The fitting of interchangeable body panels or alternative weaponry is allowed between bouts providing changes can be done within a 20-minute time-frame. Interchanging of such panels or weapons cannot be done during bouts. Body panels must be the same as the ones removed. Adding extra defensive equipment is forbidden. All interchangeable weapons must not incorporate additional defensive items. All weapons must be declared and logged on the technical check sheet. Failure to do this will result in extra weapons being excluded."

- The official Robot Wars rules from Series 7 on interchangeable weaponry

Interchangeable Weaponry is a system where a robot can be modified between battles, allowing the team to change its weaponry. The Robot Wars technical rules allow this, as long as;
 * The weapons did not push the robot over the weight, height and width restrictions.
 * The weapons were offensive additions rather than defensive additions.
 * The team declared all the weapons they could use before the tournament.

The first robots to use interchangeable weaponry on the show were Roadblock, which had interchangeable blades for their rear saw weapon, Killertron, with its double-headed pickaxe and unused mace weapon, and Shogun, which had side spikes which were interchangeable with spikes of different sizes. All three robots first appeared in the first ever episode, Heat A of Series 1.

The most successful robot to use interchangeable weaponry is Series 6 champion Tornado, which relied on a variety of different weapons - including a spinning drum, a scoop and an 'anti-crusher weapon' - to succeed in later series. Other successful competitors to use them in recent series include the robots of Team Shock and Series 9 runner-up Eruption, although the latter mainly relied on its rear-hinged flipper during battles.

Advantages and Disadvantages
Advantages
 * Interchangeable weaponry gives a robot a wider range of attacking options and tactics than what can be offered with a single weapon. For example, in Series 9, Behemoth's interchangeable scoop, angled ploughs and grabbing arms gave the team the choice of flipping their opponents with the original scoop, deflecting blows from spinning weapons with the angled ploughs, or pinning down opponents with the grabbing arms.
 * Interchangeable weaponry allows the robot to be modified depending on which opponent(s) it faces. For example, in Series 9, Behemoth used one of its angled ploughs, designed specifically to deflect blows from spinners, which helped it to defeat PP3D.
 * If one weapon proves ineffective, it can easily be replaced with another. In Series 4, the X-Terminator team found that the robot's axe weapon was not damaging enough, so they changed it to the scoop flipper, which helped X-Terminator win its Heat Final against Behemoth.
 * Alternatively, interchangeable weapons can easily be swapped round when one breaks. This happened to Big Nipper in Series 8, which resorted to using its crushing claws against TR2 after its spinning disc was badly damaged during its Group Battle.
 * Interchangeable weaponry can bring a 'surprise factor' to a robot, that its opponent(s) may not anticipate. Tornado's horizontal bar spinner was concealed from other roboteers until it was first used.

Disadvantages "Putting a grabber of that type onto the robot for a critical match was a very poor decision ... I was so annoyed with the rest of the team for making that decision not to go with a guaranteed win, with using the scoop. It's proven that, sometimes, innovation doesn't pay out - sometimes, it's best to use what you know works."
 * Each interchangeable weapon will have its own disadvantages, and not all will necessarily be suited for certain opponents.
 * Adding an extra weapon to a robot can adversely change a robot's abilities. For example, the spike used by X-Terminator in Extreme 1 prevented it from self-righting, a problem which could have been avoided if it was not fitted at all.
 * Similarly, Storm 2 would not have been able to run inverted with the flywheel.
 * Some custom prepared weapons were not allowed to be used as they violated the rules. In Series 6, Team Tornado were not allowed to use their anti-spinner weapon against Hypno-Disc, and their anti-crusher weapon was banned after Extreme 2, with both interchangeable weapons being deemed to be defensive additions.
 * Buying and/or building multiple weapons for a robot is more expensive and time-consuming than developing a single weapon.
 * Having interchangeable weapons sometimes proves unnecessary, as one weapon can prove much more effective than the others. For example, in Series 1, Killertron had a mace as well as an axe. However, the axe proved effective, so the team decided to not use the mace, and only brought the axe to subsequent wars.
 * Mixing weapons up gives roboteers less experience with each weapon and how it will operate against a type of opponent. In Series 8, Gabriel experimented with a battle axe which actually proved less effective in its Head-to-Head against Ironside3 after getting caught in the flame pit. As a result, Team Saint reverted to using Gabriel's tried-and-tested sword for its later battles.
 * Some interchangeable weaponry can prove ineffective when used. For example, in Series 9, Behemoth's grabbing arms failed to pin down their opponent properly when used for the first time against Cherub, leading to it losing the battle.

- Anthony Pritchard on the failure of the grabbing arms

List of Robots with Interchangeable Weapons
Robots are listed alphabetically. Robots which are not heavyweight entries are listed with a green background.

Trivia

 * In Series 7, Ripper's flipper was said to be interchangeable with a disc and an axe, but John Findlay later revealed that this was not actually true, and that he had made it up for the benefit of viewers.