The scoring is based on time, the faster the better, and there are bonus reductions for a variety of operating modes such as functioning autonomously, returning to home base, starting with a smoke detector-like buzzer sound, and navigating around yellow cylinders representing pieces of furniture. There are also penalties for bumping into walls or the candle. The robots are computer controlled and operate without intervention once started. Contestants exhibited a wide variety of ingenious robots. Some were precisely machined while others had a decidedly home-brew appearance.
Construction materials vary from aluminum to wood, plastic, modified toys and Legos.
There is no substitute for innovation and every year contestants confirm this with a wide variety of approaches. Bases Some are fast, some are slow, some are round, some are rectangular and some defy description. The bases are driven with either DC or stepper motors, and a variety of gearing systems. One of the more successful Lego designs used an X-Y drive system with two sets of wheels that ran perpendicular to one another. The robot lifts and lowers itself to employ the alternate wheel sets.