Antweights are a class of fighting robot that has to weigh 150g or less and fit inside a 4 inch (approx. 10cm) cube[1]. In the United States of America they are known as Fairyweights[2]. Examples of Antweights can be found in the Antweight Database.


The first ant Toecutter was built by Adam Clarke who set up the original 100g, 4” cube limit. After this initial robot, several other Antweight robots were built around basic rules which were now 150g and fit in a 4” cube. This extra weight allowed more weaponry and reduced the cost of the robot. The first Antweight World Series took part on 26th September 1999 with 6 ants in attendance. It has now been running for over a decade with the 30th World series, celebrating ten years of the competition, taking place on the 14th of November 2009[3].


Antweights were designed to be a simpler, cheaper and more convenient path into robot combat. Many early Antweights were built from standard radio control gear, such as servos and receivers. A simple Antweight could be built for under £100 by almost anyone.

As Antweights have evolved, more advanced systems have been used within them. Many robots now use motors and speed controllers designed specifically for them. Other technologies now common place in Antweights include lithium batteries, brushless motors, speed controllers and micro radio gear. However, many robots still enjoy a degree of success using standard radio gear.

The Antweight Rules

Antweights follow the Antweight World Series Rules which are a set of rules geared specifically for Antweights. Antweights are currently the only weight class officially recognised by the Fighting Robot Association that do not use the FRA rule set. The Antweight Rules are maintained by the Antweight World Series Committee. The latest revision of the rules is version 4.1.

The latest version of the rules can always be found here: [4]


Over the years, Antweights have sported various different types of weapons, the most popular are listed below:

Unlike in Robot Wars, robots with no weapons (also known as ”static robots”) have always done fairly well in the competitions, largely due to the fact that at least 50% of an Antweight arena must be a drop off zone, so it is very easy to push the other robot out of the arena to win.


Antweight World Series (AWS)

The Antweight World Series was the first Antweight event, and is widely considered to be the most important Antweight event there is. It takes place roughly every 3 months, with the venue and organiser alternating with each event. It usually takes the form of a knock-out style competition, however, this is at the organisers discretion.

The eventual winner is presented with the Antweight World Series trophy, and the title of AWS champion. In recent events, it has also been decided to include a minisumo competition along side the Antweights. In minisumo, autonomous robots try and push each other off the arena[5].

Reading Robot Club (RRC)

Reading Robot Club is run by Simon Windisch, and is another regular Antweight event[6]. It is also held roughly every 3 months, and seen as a less competitive event. It also focuses less on combat, and more on other disciplines such as Football, Speedway and Sumo.

Antweights on TV

Antweights have appeared a number of times on television. Ants played a part in both Robot Wars Extreme series, battling in their own mini Robot Wars Arena. Robot Wars Extreme Series 1 was the first time that Antweights had really been seen on TV[7], although an ant caused a stir during Series 3 when it was found in the audience.