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Official Q&A: VRC 2023-2024: Over Under

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G13 - Tipping


Dan Cieslak
29-Aug-2023

<G13>

In many of the early season matches, there seems to be many more robots tipping over and becoming immobilized that in recent years.

For emphasis, G13a specifies:

VRC Over Under is intended to be an offensive game.Teams that partake in solely defensive or destructive strategies will not have the protections implied by <G13> (see <G14>). However, defensive play which does not involve destructive or illegal strategies is still within the spirit of this rule.

There are at least 2 scenarios (with permutations) I would like clarification on as a referee:

  1. Red Robot and Blue Robot engage in a pushing battle in one of the "side alleys" of the field. In the course of the pushing contest, the Robots start to raise up, and eventually one robot winds up on its back, immobilized. There are many permutations of this, namely:

A. Red Robot has a Triball while Blue Robot does not. Assume the pushing contest goes back and forth between each team's Offensive Zone.

B. Both Red Robot and Blue Robot possess a Triball. Assume the pushing contest goes back and forth between each team's Offensive Zone

C. Neither Red nor Blue Robot possess a Triball. Assume the pushing contest goes back and forth between each team's Offensive Zone.


  1. Red Robot and Blue Robot are in the middle of the field, each in their Defensive Zone. The Blue Robot attempts to cross the Barrier while the Red Robot attempts to prevent this movement. In the course of the interaction, the Blue Robot tips over and becomes immobilized.

A. The Red Robot possesses a Triball while the Blue Robot does not.

B. The Blue Robot possesses a Triball while the Red Robot does not.

C. Neither possess a Triball.

D. Both possess a Triball.

E. Neither possess Triballs, but one or both are pushing them across the center barrier and / or trying to prevent the other Robot from doing same.


Additionally, G13c specifies:

This applies both to Teams that are driving recklessly or potentially causing damage, and to Teams that drive around with a small wheel base. A Team should design its Robot such that it is not easily tipped over or damaged by minor contact.

To what degree, if any, are robots that are designed without features to prevent themselves from being tipped over unable to benefit from G13 should their robot be tipped over during "normal" robot-on-robot interaction? For example, a Robot that winds up every match on its back would seem to have a design flaw. Such flaws may not be apparent during Robot Inspection, and may not be exposed until the Robot has played several matches.

If the Alliance that tips over an opposing Robot then attempts to provide aid (nearly immediately) to the tipped over Robot (e.g. makes efforts and/or succeeds in righting the Robot), should the Head Referee take that into account when determining whether the interaction is "Intentional and/or egregious tipping"

Thank you for your time.

Answered by committee
14-Sep-2023

Thank you for your question, which highlights the importance of having human Head Referees who are able to observe Matches and make snap judgments based on the available information and the context of the Match. As described in rule <G13b> and bolded for emphasis:

VRC Over Under is also intended to be an interactive game. Some incidental tipping, Entanglement, and damage may occur as a part of normal gameplay without violation. It will be up to the Head Referee’s discretion whether the interaction was incidental or intentional.

Ultimately, any potential tipping scenario can only be judged within the larger context of the Match. The red box following rule <T1> is particularly relevant to your question, and should be remembered by all participants:

The rules contained in this Game Manual are written to be enforced by human Head Referees. Many rules have “black-and-white” criteria that can be easily checked. However, some rulings will rely on a judgment call from this human Head Referee. In these cases, Head Referees will make their calls based on what they and the Scorekeeper Referees saw, what guidance is provided by their official support materials (the Game Manual and the Q&A), and most crucially, the context of the Match in question.

The VEX Robotics Competition does not have video replay, our fields do not have absolute sensors to count scores, and most events do not have the resources for an extensive review conference between each Match.

When an ambiguous rule results in a controversial call, there is a natural instinct to wonder what the “right” ruling “should have been,” or what the GDC “would have ruled.” This is ultimately an irrelevant question; our answer is that when a rule specifies “Head Referee’s discretion” (or similar), then the “right” call is the one made by a Head Referee in the moment. The VEX GDC designs games, and writes rules, with this expectation (constraint) in mind.

Regarding your final question, in which an Alliance tips over an opponent and then takes immediate action to right them, that is part of the larger context of the Match that the Head Referee should consider when determining whether or not a Violation has occurred.