Robot Combat Rules
Robot combat has several organizations that develop rules of play. These rules typically cover both robot construction and match procedures. However, there is no national or global league or governing body defining local rules. The sport is still young, and each event can choose its own rules, experiment, and innovate.
For most bot builders, travel to many locations to compete isn't practical, so multi-city leagues are unusual, and so there is limited standardization in arenas. Rules have instead focused on ensuring things like fair fights, impartial judging decisions, and most of all, uniform standards of safety.
Before building your robot, figure out which event you are building for. Most event organizers will use standard rules from one of the groups listed below, but will make changes for their arena, their judging situation, or other local requirements. Get the rules from your event. Read them carefully and check for exceptions or changes to the standard rules that may affect you. Also be aware that any event organizer may disqualify a robot if they feel something about it is unsafe, so if you think you've found a loophole or workaround to make your bot more destructive, clear it with the event organizer before you show up.
Here are some of the organizations which have published rules and guidelines for robot combat events. You can freely download and read any of these rules.
- Standard Procedures for the Advancement of Robot Combat, publisher of numerous resources for arena construction, competitors, judges, and more - most commonly used rules for SPARC Robot Construction and SPARC Match Procedures
- Northeast Robotics Club, a prominent competitive organization - NERC Rules
- Fighting Robot Association is centered in the UK - most events in Europe use their FRA Rules
- Norwalk Havoc Robot League has their own NHRL Rules
- BattleBots is a TV show with 250 pound fighting robots - BattleBots Rules are adjusted yearly
(National Robotics League is not on this list because only students on authorized teams may participate.)
There are several different methods to judge a robot combat match.
Generally, if a robot is disabled, thrown out of bounds, or unable to travel normally on the arena floor, the judges will determine that the robot has lost the match.
If neither bot is disabled or disqualified, judges must render a decision. This is usually done with a point system weighted to bring out the best in bot designers and drivers, but designed never to result in a tie. For example, judges under SPARC rules give points for Aggression (5 points), Damage (6 points) and Control (6 points), but shared between two opponents.
If both robots appear to have suffered equal damage, each would receive equal points (3 each) using the SPARC rules. If both also exhibited equal control ability, both would receive 3 points. The judges must weigh which driver was the more aggressive to break the tie. However, it's possible on some point scoring systems for 2 of 3 judges to believe one robot has won, but the 3rd judge assigns enough points to override them.
SPARC offers example videos with judges commentary that can help new judges understand how to assign scores.
Event organizers may make exceptions for specific issues caused by the arena itself. For example, if bots gets jammed against the walls due to a design flaw or normal arena wear and tear, judges may direct opponents to stop the match and free a bot that gets stuck instead of counting that bot out of play. The bot's driver is expected to avoid that situation in the future.
A "one free unstick" rule may also apply to bots that have become entangled or locked together.
Judge's Call variant
Many events have done away with the detailed scoring system and simply have each judge indicate which bot they felt won the overall match. While this may lead to more consistent results, some builders get frustrated without scores to indicate why they won or lost the match. Different events also have different allowances for judges to talk with each other when making decisions. Some events want each judge to come to their own conclusions independently, while others think it better to have judges compare notes and discuss the results.
Matches can also be judged by a simplified system based solely by the state of the robots at the end. For example:
- 2 points awarded to the survivor when the other bot is knocked out, disabled, or falls into a pit (Win)
- 2 points awarded if the opponent is disqualified or forfeits the match before it starts (Bye)
- 1 point awarded to each bot remaining after time expires and the match is over (Tie)
- 0 points for a bot that is knocked out, disabled, or falls into a pit (Loss)
- 0 points awarded to a bot that is not ready for combat or is disqualified (Forfeit)
This system is ideal for informal matches and usually doesn't require impartial judgment. However, it's important that the term "disabled" is clearly defined and understood by all participants.
Since all types of bots must be able to disable their opponent, it's best if this variant is played in an arena with pits or other hazards that will potentially allow wedge bots and partially damaged bots a chance to win.