What kind of cereal should we use?

Any brand and size of cereal may be used in machines for local and regional competitions. However, cereal and cereal boxes will be provided to all participants in the RUBE GOLDBERG MACHINE CONTEST FINALS competition.

Participants are required to use the provided cereal and cereal boxes at the Finals event.

Cereals to be used in the Finals competition will be sent to all Finals participants to incorporate into the Finals machines.

PLEASE NOTE: Hosts and Team Leaders – As soon as the winners of the Regional Contest are determined, please forward the following information to rube@rubegoldberg.com: a) the cereal used in the winner’s machine, b) the size of the cereal box. and c) the name, contact info and COMPLETE mailing address to where the package should be sent.

Please clarify the task.

It is up to you to interpret the task in a way that will impress the judges. If you were a judge, would you find it more impressive if a machine poured both the cereal and milk into a bowl, or just the cereal into a bowl?

Can we utilize a human in our machine?

A person may be part of the machine, but must be counted as part of the machine volume as long as they don’t extend or move outside the maximum length, width, or height restrictions during competition. A persons volume should be considered 2 foot by 2 foot by their individual height and added to the physical machine volume. This total volume must not exceed the 300 cubic feet stated in the rule book. In addition, a person who is included as part of the machine, may not interfere with the machine’s operation once the machine has started. Any touches, blowing, sneezing, or interaction that causes the machine to be manipulated may be considered an intervention by the referees.


The person needs to be added to the machine volume (regardless of whether they are standing on the floor or standing on the machine).

If a person part of a machine is standing on the floor, their volume should be counted as a 2’ x 2’ square multiplied by their individual height (or the height of the tallest element of the machine, whichever is greater).
If a person part of a machine is standing on the platform of the machine, then the footprint calculation for the machine would not change but the height would still be the height of the person or the tallest element of the machine, whichever is greater.

As 1st place Team at our regional, are we allowed to add to our machine before we compete at Finals, as long as the machine stays within the regulations?


Does completing the task have to be the absolute last step?

Any steps that occur after the task has been completed do not count. However, you are free to have as many steps after the zipper has been zipped, even though they do not count toward your total number of steps.

What is repeatability?

Repeatability is how consistently a machine runs across multiple runs. A machine that works perfectly every time is ideal, but a machine that fails in the same place each time it runs is much easier to debug than a machine that fails in different places every time.

What is reliability?

Reliability is how well a machine runs in a single run. For example, a single machine run with no interventions is scored higher than a single machine run with 2 interventions.

Are gasses and steam allowed to exit the boundaries of the machine?

Yes, as long as they are not hazardous. For example, fog is allowed but steam that is hot enough to burn someone is not allowed.

What is an intervention?

Any physical touching or action to continue the operation of the machine through human interaction after the machine begins its Contest run.

Example: Your machine stops because one step does not trigger another. A team member interacts with the machine through a physical touch or other device to trigger any steps that follow.

What is "a step"?

A step in the machine is a transfer of energy from one action to another action. Identical transfers of energy in succession should be counted as 1 step.

Example: A sequence of dominos hitting each other should be counted as 1 step. Counting 100 dominoes as 100 steps is repetitive and not in the spirit of Rube Goldberg.

Can a machine include a remote control device as a step in the machine?


Can a machine be started with a cell phone/remote control/RF device?


Can a team have a banner or prop outside of their area which is not used by the machine?

No items may be outside of the area used by the machine, and all items (including banners) inside the machine area count toward the volume of the machine.

How are branching steps counted in a machine? Can they count?

No — only one linear sequence of steps can be counted. Branching steps are not advised as they make machines hard to follow.