Critter Ball and Metric Unlimited Crunch Rules v0.6

Governing Body



A. No Cheating!
This covers spirit-of-the-competition type violations. Cheaters may be required to perform menial labor for the remaining duration of the convention in order to save face and prevent or reduce public ridicule.

B. Frankenstein Rule:
If a Critter proves sufficiently offensive to the audience, the audience may (at their discretion) light torches, take pitchforks in hand, make pretty fireworks with the Critter, and throw its perpetrators into the nearest dumpster. The Critter itself can be vile; it simply cannot perpetrate vile acts toward the audience, or OVERLY offensive damages toward its opponents (such as spraying it with corrosive bile that will dissolve into metal mush and kill the audience through toxicity). Likewise, overreacting audience members would be frowned upon. I.E. offensive is good so don't jump the first Critter and perpetrator that manages to disturb your sensibilities a little bit unless you wish to be jumped by fellow audience members who get their own sensibilities disturbed by having their show ruined before its climax.

I. Critters:

{Critter Ball} Critter size will be limited to 12"x 12" x 12".
{Metric Unlimited} Critter size will be limited to 1m x 1m x 1m.

The Critter may deploy appendages beyond these dimensions after the start of combat. The cubic space rule applies only at the start of each combat. B.
{Critter Ball} Critter weight limit is 20lbs.
{Metric Unlimited} Critter weight will be limited only by structural

C. Critters may be powered by any source socially acceptable (OSHA approved) for indoor use. Critter power sources must be 100% contained in the Critter and packaged appropriately for the expected abuse. D. Control pendants, cables, or other external control devices do not count against the Critter weight or size. Critter control may be by any means not prohibited by rules I(C) or II(E). E. All Critters must, at the beginning of each combat, be capable of movement at a rate of at least 1/2 inch per second. F. No Critter may, under any circumstances, present a hazard to the judge(s), spectators, or the opposing perpetrator(s). No Critter may, in its operation, cause damage to anything other than itself, the opposing Critter, or the combat surface. G. All entries must conform to the general rules of the hotel and the convention. H. All Critters will be subject to a technical inspection prior to competition. Failure to disclose any operating principle shall be grounds for immediate disqualification. Judges may restrict any function deemed excessively hazardous.


{Critter Ball}
A. The combat surface is defined as the surface of an unfinished wood platform measuring 15' by 10', with a 4" rim on the long sides to prevent the ball from falling off except at the goals (the short ends). The drop from the top of the combat surface to the floor shall be no more than 6".

{Metric Unlimited}
A. The combat surface will be plywood covering concrete or asphalt. It will measure 30' by 30'.

{Critter Ball}
B. The combat volume is defined as the combat surface and the airspace above it to the height of whatever ceiling is present.

{Metric Unlimited}
B. The combat volume is defined as the combat surface, and the airspace above it to a height of 1/3 of the distance to the nearest spectator, with a minimum of 8 feet high.

C. Leaving the combat volume entirely is prohibited. Major portions of the Critter may leave the combat volume provided that some part of the Critter is within the combat volume. Projectiles must remain entirely within the combat volume.

D. No contact with the ceiling is permitted, especially when outdoors under the open sky.

E. No part of any perpetrators' body may impinge on the combat volume during combat, unless s/he's willingly sacrificing hir life to hir machine to end it all. This is legally frowned upon, but good publicity for promoting later competitions.

F. Projectiles: A projectile is defined as an object thrown with the expectation that its kinetic energy will affect its target. Projectiles, if employed, must be tethered. Tethers must be no longer than 1/2 (one half) the longest dimension of the combat surface. Tethers must be proven to be strong enough to hold their projectiles!

G. Non projectile loose items may be deployed from your Critter but must be picked or cleaned up, to the best of your ability, after combat. Deployables of this nature must be safe for humans and environmentally friendly. There should be no acid dumps or oil spills soaking into the hotel floor or parking garage.

A. Judges shall be impartial non-participants.
B. Judges may declare a contest completed at any time.
C. Judges' decisions are final.


A. The manner of elimination (single elimination, double, etc.) will be at the discretion of the competition organizers.

B. Critters will start on opposite sides of the combat surface with the aft end of the Critter even with the edge of the combat surface.

{Critter Ball}
C. The ball will start in the exact center of the playfield, and will be a standard tennis ball.

D. Victory:

To claim victory your Critter must show mobility and be within the combat volume. You will immediately be declared defeated if your Critter has been rendered immobile, has entirely left the combat volume, or if any attached part of your Critter has come in contact with any restricted surface or the floor.

If both Critters are immobile the Critter controlling mobility will be declared the winner. In cases where there is no winner both Critters shall receive a loss.

Absent a clear victory, combat will proceed for 3 minutes after which the judge(s) may declare a winner, no winner, or grant more time.

{Critter Ball}

Number of goals to win will be determined by the judges as necessary to fit the number of entrants into the time allowed. Destruction of the ball will count as a goal against the Critter which destroys it.

D. No Critter shall be required to compete within 10 minutes of its previous combat to permit recharging of batteries, replenishment of expendables, damage repair, etc. Machines requiring excessive time to prepare for their next combat, may be declared defeated by forfeit, at the judge(s) discretion.



The following are some clarifications and examples to aid builders in the Critter events.

Power Sources
Combat Surface
Spirit of the Rules
Expected Abuse
Autonomous Critters


Power Sources:

{Critter Ball}
The most obvious is batteries, but don't let yourself be limited. Any source designated by OSHA as suitable for indoor use is okay. Model aircraft and car motors (ie, "glo plug") engines are not acceptable, due to their unhealthy exhaust and hazardous fuel.

{Metric Unlimited}
Any source deemed safe and socially acceptable will be allowed, such as gasoline engines.

Fuels must be safely contained, and perpetrators will be responsible for bringing appropriate safety/cleanup measures for any oddball power sources. Ask in advance if you want to confirm acceptability of questionable Critters.

{both} This includes, for example, a four-stroke internal combustion engine powered by propane. Please include a tilt switch to shut it off if it is turned over, where appropriate.

Combat Surface:

Check with the organizers before spreading oil slicks or deploying chainsaws. Clean up will be accomplished by the Critter perpetrator(s). Damage must not be done to the hotel floor or concrete/asphalt surface.


In the interests of keeping the construction simple, self-retraction of deployed appendages is not required. That is, you may hand-prep your Critter to fit the specified cube, although it must fit the cube unassisted. Deployments must be an automatic or remotely triggered function, occuring after the start of combat.

Spirit of the Rules:

It is not the wish of the organizers to disqualify entries on niggling technicalities. Rather, the rules should be interpreted as broadly as possible to permit the widest variety of endeavor. (Nudging the high side of the weight or volume limit will not automatically disqualify you, but judges will not go rampant with exemptions.)


A stream of liquid is not a projectile. Something that is tossed, so as to disperse or place it across the table, is not a projectile. Use common sense and don't quibble. Projectiles are items which are intended to cause damage or disruption with the kinetic energy imparted at the time of deployment, rather than by their simple presence or autonomous functions. Deployments with autonomous functions must still meet safety requirements -- no claymore landmines please.

Expected Abuse

(From paragraph 1C) Note that your Critter may, during the course of competition, be severely damaged or even destroyed. Past competitions have seen Critters equipped with pneumatic cylinders, spear-throwing CO2 cannons, and flame throwers. Please consider this when packaging your power source if it involves such potential hazards as acid (batteries), flammable liquids (engines), or plutonium (reactors).

Developing an emotional attachment to your Critter is NOT recommended!

Abuse of spectators or opposing perpetrators is disallowed.

Autonomous Critters:

{Critter Ball}
At present there is no separate division for autonomous Critters. Autonomous control is allowed and encouraged but, for now, these will compete with person controlled Critters. This can put such Critters at a disadvantage. Dangerous weapons or functions of Critters must be manually controlled, or have manual safety overrides.

{Metric Unlimited}
Due to the inherent hazard of out-of-control killer robots attacking spectators, judges, opposing perps, or building infrastructure, autonomous Critters are disallowed in the Metric Unlimited event.


Critter Ball/Metric Unlimited Crunch Governing Body

If you have questions or comments about the rules, or the tournaments, please write to:

Death Equinox
Critter Rules
PO Box 581
Denver, CO 80201

If questions become frequently asked, they will be added to a FAQ at this url.

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