Robotics Education & Competition Foundation
Inspiring students, one robot at a time.

Official Q&A: VRC 2020-2021: Change Up

Usage Guidelines All Questions

<SG8> Interplay Between Momentary Possession and Stopping All Other Robot Actions


- - (Event Partner)
1 year ago

This question is asked on behalf of a fellow VEX Forum user.


This is a follow-up to Q&A 608 and, to a lesser extent, Q&A 601. The ruling given here may also be relevant to a ruling on Q&A 597, whenever one is issued.

The relevant portions of <SG8> are repeated below:

Possession is limited. Robots may not have greater‑than‑momentary Possession of more than three (3) Balls of its opposing Alliance's color at once. When two Robots from the same Alliance are working in tandem and blocking Balls, those Robots may not Possess a total of more than six (6) Balls of its opposing Alliance's color at once.

Robots that violate this rule must stop all Robot actions except for those actions that are attempting to remove the excess Ball.


Suppose a Robot is in Possession of more than three (3) Balls of its opposing Alliance's color for a momentary period of time before the excess Ball is ejected.

Which of the following interpretations, if either, is correct?

  • The Robot must immediately stop all Robot actions except for those actions that are attempting to remove the excess Ball as soon as Possession of the excess Ball begins, even though the Possession of the excess Ball ultimately proves to be momentary in total duration.

  • Because the Possession of the excess Ball is momentary, the Robot does not need to stop all Robot actions except for those actions that are attempting to remove the excess Ball. That is, the Robot may continue scoring or performing other actions as desired while momentarily Possessing the excess Ball. By extension, this interpretation would imply that the Robot must stop all Robot actions except for those actions that are attempting to remove the excess Ball only after the Possession of the excess Ball becomes greater-than-momentary.

Answered by Game Design Committee

Suppose a Robot is in Possession of more than three (3) Balls of its opposing Alliance's color for a momentary period of time before the excess Ball is ejected.

Which of the following interpretations, if either, is correct?

  • The Robot must immediately stop all Robot actions except for those actions that are attempting to remove the excess Ball as soon as Possession of the excess Ball begins, even though the Possession of the excess Ball ultimately proves to be momentary in total duration.

This interpretation is correct.

We will not be providing a blanket definition for a length of time that is considered "momentary", nor will we be defining how Robot actions (which are not related to ejecting the excess Ball) must be stopped. If a Head Referee finds themselves in a scenario where they must make a judgment call on the severity of an SG8 violation, we would reiterate the remainder of SG8 which was not quoted in your question:

Minor violations of this rule that are not Match Affecting will receive a warning. Match Affecting offenses will result in a Disqualification. Teams that receive multiple warnings may also receive a Disqualification at the Head Referee’s discretion.

It is also important to remember that G3 always applies when a Head Referee is attempting to judge an edge-case scenario:

<G3> Use common sense. When reading and applying the various rules in this document, please remember that common sense always applies in the VEX Robotics Competition.