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Official Q&A: VRC 2018-2019: Turning Point

Usage Guidelines All Questions

209: Trapping G14 clarification


2019F
14-Jan-2019

I would request that GDC help clarify how trapping should be regulated correctly. Here are the pertinent rules and apparent confusion.

Game manual Trapping definition (Page 13) TrappingA Robot status. A Robot is Trapping if it has restricted an opposing Robot into a small, confined area of the field, approximately the size of one foam field tile or less, and has not provided an avenue for escape. Trapping can be direct (e.g. pinning an opponent to a field perimeter wall) or indirect (e.g. preventing a Robot from escaping from a corner of the field).

<G14> No Trapping for more than 5 seconds. A Robot may not Trap an opposing Robot for more than five (5) seconds during the Driver Controlled Period. A Trap is officially over once the Trapping Robot has moved away and the Robots are separated by at least two (2) feet (approximately one [1] foam tile). After ending a Trap, a Robot may not Trap the same Robot again for a duration of five (5) seconds; if a Team does Trap the same Robot again, the count will resume from where it left off when the Trapping Robot initially backed off.

From videos- The requirement is added that a robot must be actively trying to escape for a trap to be in effect.

There seem to be two areas where these rules seem to be often misapplied.

  1. When the trap should start. What I often see is that the trap is not declared until the defensive robot is actually pinning the opposing robot.

  2. When the trap should end. What I often see is that as soon as the trapped robot is able to move significantly, or an escape path becomes possible, counting stops. Basically, the same criteria are applied to initiating the trap as ending it even thought the rules don’t seem to support this interpretation. The concern with this application is that especially in this game with three other 18-36 inch wide robots and large and protruding field elements, mobility is already significantly impeded. Not requiring a full tile can prolong the impact of a trap much longer than 5 seconds if a trapped robot is not given some room to maneuver.

Based on this, I believe it would be helpful to clarify the following questions.

Is it required for a defensive robot to be in direct contact with another robot to be trapping?

Once a trap is declared, when does the timed count stop (more than one if appropriate)?

A. When the defensive robot either moves a full tile away or the trapped robot is not trying to escape.

B. When the defensive robot pulls back enough for the trapped robot to move even if its obviously not a full tile?

C. As soon as there is a path of escape?

D. Other?

When should the count stop (more than one if appropriate)?

A. When the defensive robot either moves a full tile away or the trapped robot is not trying to escape.

B. When the defensive robot pulls back enough for the trapped robot to move even if its obviously not a full tile?

C. As soon as there is a path of escape?

D. Other?

If a defensive robot initiates a trap in a confined area and becomes unable to separate a full tile, does this negate their requirement to move back a full tile before the trap\count is stopped?

A. No, the defensive robot assumes this liability when opting to play defense and should avoid trapping when they are uncertain that they can comply with the rules to separate a full tile prior to a 5 count.*

B. Yes, so long as robot that initiated the trap is doing everything possible to avoid contact.*

*Neither of these are assumed to change the obligation that the trapped robot must be continuing to attempt to escape. If the trapped robot were to attempt to produce or prolong either of these situations by doing anything other than attempting to escape the trap would be resolved. This strategy would also be attempting to cause another robot to perform an infraction and a violation of G11.

Answered by Game Design Committee

Thank you for the well thought-out and descriptive post, complete with the necessary reference materials. Before answering your specific questions, please remember that the VEX Robotics Competition is a volunteer-driven program with over 1700 events across 50 countries each season. While the Game Design Committee and the REC Foundation strive to continuously improve our training materials, requisite certifications to run an event, and overall consistency between events, providing absolute guidelines for subjective topics is one of the largest challenges that we face each year.

To be more specific - the interactive and dynamic nature of a VEX Robotics Competition game makes it impossible to provide absolutely black-and-white clarifications of inherently non-black-and-white topics, such as defensive interactions. If everything in a game was absolute and explicitly clear, then the role of a Head Referee to provide in-the-moment interpretations would not be needed!

So, with that in mind, let's dive in. These answers represent the intent of the Game Design Committee within the guidelines and training materials that we have provided for VRC Turning Point referees, not an ultimate expectation or guarantee that all Head Referees will interpret a given edge case in exactly the same way.

Is it required for a defensive robot to be in direct contact with another robot to be trapping?

No. As demonstrated in the Referee Training video, and defined in the definition of Trapping as "indirect" Trapping, direct contact is not required for a Trapping count to begin.

Once a trap is declared, when does the timed count stop (more than one if appropriate)?

A. When the defensive robot either moves a full tile away or the trapped robot is not trying to escape.

B. When the defensive robot pulls back enough for the trapped robot to move even if its obviously not a full tile?

C. As soon as there is a path of escape?

D. Other?

The intent is for a combination of A and C, although a "path of escape" is very difficult to define. The demonstration in the Referee Training video is one example; a Robot which is being Trapped against the field perimeter may technically have an instantaneous path of escape while a Trapping Robot maneuvers around them, but it is not a realistic expectation that the Trapped Robot would be able to escape in that brief moment. This is where some amount of referee subjectivity is required, to interpret the context of a given Match and the interactions they are seeing on the field.

When should the count stop (more than one if appropriate)?

Although you seem to be implying a specific and/or subtle difference between this and the last question, we are not quite understanding what you are getting at. If the answer to the previous question was not sufficient, please feel free to rephrase and re-submit.

If a defensive robot initiates a trap in a confined area and becomes unable to separate a full tile, does this negate their requirement to move back a full tile before the trap\count is stopped?

A. No, the defensive robot assumes this liability when opting to play defense and should avoid trapping when they are uncertain that they can comply with the rules to separate a full tile prior to a 5 count.*

B. Yes, so long as robot that initiated the trap is doing everything possible to avoid contact.*

The intended answer to this question would be your option A, with the pretty significant disclaimer that it is impossible to rule absolutely on snapshot descriptions of hypothetical scenarios. There are many scenarios where a Head Referee could subjectively interpret that a Trap is not occurring. Take the following two examples to illustrate this point:

  • Picture two Robots who drive into the "lane" between the Platforms and the Field Perimeter from opposite directions, contact each other, and become unable to get out of the "lane". However, both Robots are clearly attempting to break free, such as by pausing driving to let the other Robot maneuver out, or verbally calling across the field to explain their movement, or rapidly turning back and forth away from the opponent. It would be a fair interpretation that neither Robot has "restricted" the other to a small confined area of the field, and no Trap should be called.

  • Picture this same scenario, except the two Robots become "stuck" because one of them turned 90', began directly Trapping an opponent against the field perimeter, and then became unable to turn themselves 90' back around due to the Trapped Robot now being there. In this scenario, your option A applies - any Robot attempting to legally Trap for less than 5 seconds should have an "exit strategy".