Starting with the lightest, there are the Fairy weight robots. These machines can weigh up to 150g - roughly equivalent to a large apple's weight. Following them are the Antweights, which have a limit of 1lb. There's also a unique category within Antweights called Plastic Ants, and these are predominantly made out of plastic.

Moving up the scale, there are the Beetle weights with a 3lb limit. The Mantis weight robots, which aren't as common, weigh up to 6lbs. The Hobby weight category allows for robots that are twice as heavy, capping at 12 lb.

At the heavier end of the spectrum are the Feather weights. These hefty contenders can weigh as much as 30 lb.

However, the weight classes have more nuance than just the raw weight. Depending on the tournament and its rule set, there might be allowances for additional weight, termed "weight bonuses". These bonuses are often provided for specific robot designs. For example, if a team fields multiple robots fighting in tandem, known as "multi-bots", they could be awarded a weight bonus. Similarly, bonuses are available for robots that opt for a legged approach instead of wheels. These so-called "walking" robots are becoming more popular and earn their bonus for their unique, non-wheeled mode of movement.

To ensure fair play and safety, robots are matched with suitable arenas for their battles. A Beetle weight robot, for instance, might be pitted in an 8 ft by 8 ft arena, while the larger Feather weight robots clash in a more spacious 16 ft by 16 ft arena. It's essential to have the right space to allow for thrilling combat while ensuring spectators remain safe. It's always a good idea to consult the event's rules for specifics regarding competing weights and arena sizes.