Two autonomous robots are placed in a ring. The robots try to avoid falling out of or being pushed out of the ring. The first robot that touches outside the ring loses the round. The first robot to win two rounds wins the match.

Mini-Sumo Robots
Autonomous Sumo robots are self-propelled and self-controlled, without tethers. After positioning and starting the robot, no remote control, power, positioning, or other help can be provided. The robot must care for itself until the round ends.

Mini-Sumo robots may have a mass of up to 500 grams. A scale will be used to measure the mass of each robot and if the scale reads 500 grams or less, the robot will be eligible for competition. Devices such as helium filled balloons cannot be used to lighten a robot.

At the start of each round, Mini-Sumo robots must not exceed 10cm in width or depth. There is no height limit and as soon as movement is allowed in a round the robot may twist, fall, or expand without size limits.</p>

At all times, robot behavior must be non-offensive, non-destructive, and non-harmful to humans, robots, and the facilities. This is an immutable principle, even if the behavior is unintentional or not by design.</p>

During inspection (and at any time during the event), the judges may require safety changes or other modifications to meet the harmlessness requirement. Harmful robots are either not allowed to compete at all or are later disqualified if potential harmful issues are proven or revealed in battle.

During the contest, the judge must determine if a robot's failure was due to its own lack of durability. Failures due to exposed wires or unsecured or flimsy parts shall be the responsibility of the robot with such weaknesses.

At all times, Sumo Robots must not:
     - Emit smoke or fire
     - Leak, stain, or soil
     - Disperse powder, grit, or grime
     - Spray, throw, or use projectiles
     - Jam, shock, or electromagnetically interfere
     - Snare, entangle, or employ nets/rope
     - Scratch, gouge, or scrape

However, as for the last point, naturally some damage occurs from
scoops, changes in starting orientation, and from the battles
themselves. This is expected and acceptable to any reasonable extent.

No flying
Sumo Robots must not fly or generate lift to isolate themselves from the ring surface.

The "no-fly" rule isn't intended to prevent a robot from having a
floating portion (such as a camera, sensor, flag, or distraction) nor to prevent jumping or other interesting behavior. The robot qualifies as long as a major portion of the robot is generally available to be pushed out by the opponent robot.

Suction, Magnets and Sticky Wheels
Use of Suction, Magnets and/or Sticky wheels as a way to increase traction is not permitted in LVBots Mini-Sumo tournaments. To determine whether a robot's wheels are too sticky the robot will be placed on a piece of paper and lifted up. If the paper lifts with the robot the wheels are too sticky.

The Ring
The ring is a large flat disc made of a smooth rigid material such as wood, aluminum, or steel. The top surface is painted black except for a white border which is approximately 2.54cm (1 inch) wide. Two starting lines in the middle are brown. The ring will be approximately 77cm in diameter.

The Contest
Our Mini-Sumo tournament will be conducted as a double-elimination tournament. All robots will be inspected to verify that they comply with the stated rules.

A Match
Matches are conducted in the ring and consist of several rounds. The first robot to win two rounds wins the match.

The better ranked robot or the robot which won the previous round is placed first on its side of the ring. The lesser ranked or the robot that lost the previous round is placed second. Once a robot is placed it can not be moved or rotated. Each robot must be placed behind its respective starting line in the ring.

Robots must have a method of being started. Typically this is done by pressing a button but can be implemented in any other way that meets the requirements. Both contestants will start their robots when the referee says 'Go' and then move away from the ring. During the round, people and objects must be kept away from the ring to avoid disturbing the robots or altering the outcome. Robots should remain motionless for at least 5 seconds after being started.

No Start
During the 5 second countdown at the start of a match, if a contestant notices that their robot has failed to start its countdown, the contestant may alert the referee and halt the countdown.

False Start
If a robot begins moving before the 5 second period is over, the robot has committed a false start and the match will be re-started. Two false starts by the same robot results in a loss of the round for that robot.

A robot loses the round when any portion of the robot touches outside of the ring.

If any piece of the robot, no matter how small or even if detached, touches outside of the ring, the robot is considered out. For example, if a nut drops off a robot within the ring, the robot doesn't immediately lose. However, if the nut is then pushed out or rolls out, the robot loses.

If a robot lands outside the ring atop a whisker, scoop or any portion of the opponent robot, the opponent robot is out. This is consistent with the policy that the robot that touches outside first is out, even if the second robot subsequently touches outside the ring.

Starting to fall or breaking the plane of the ring isn't considered out.
Some portion of the robot must actually touch outside the ring.

Contestant Stoppage
After a round has started, either contestant can stop the round and loses that round.

Referee Stoppage
At the referee's discretion, the referee may restart a round if:
     - 3 minutes have expired
     - No progress has been made for some period of time
     - The robots are entangled or otherwise deadlocked.

The referee may choose to end a round and choose the winnner if:
     - Smoke, fire, damage or any other violation has occurred.
     - No progress is likely to be made even if the round is restarted.