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Game Rules and Game Play - Answer Thread

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  • Blocking Access to Center Goal

    Originally posted by FTC9387
    In the rules is states: "<GS18>During the End Game, an Alliance may not Block Access to the opposing Alliance's Center Goal. If this occurs,
    the offending Alliance will incur a Major Penalty." If a robot is in position to score in the center goal during the end game period, and then an opposing alliance team member pushes that robot to the side to prevent it from scoring but then that opposing team robot is in the space that the scoring robot needed to be in, would that be considered blocking access to the center goal?

    A: Merely being in position below the center goal would not be sufficient to be considered blocking access. If the defensive robot then continued to push the offensive robot, keeping it away from being able to access the Center Goal, <GS18> penalties would apply.


    • Aggressive Defense at Center Goal

      Originally posted by FTC4537
      At a recent event, a blue robot parked under the red center goal during the endgame and blocked access to the tube for the first 15 seconds of the endgame. After repeated warnings, the blue robot finally moved back. When the red robot moved into position, the blue robot repeatedly rammed it (and received a warning). After about 10 hits, the red robot's arm finally broke off and it was disabled. No penalties were assessed because the blue team had asked the head ref beforehand if ramming was allowed during the endgame and was told it was an acceptable type of play. As a ref myself, I'm curious if blocking and ramming (with the obvious intent to disable) during the endgame is something we should be more lenient on this year. (If the reaction of the crowd is any indication, I think the concept of gracious professionalism took a hit with the performance.)

      A: In general, it is not possible for us to comment on what was or wasn't called at a particular event. FIRST Tech Challenge is an interactive robot game. Some robot to robot contact should be expected, and should be designed for.

      If, in the determination of the referees, the blue robot was blocking access to the red center goal for 15 seconds, the referees should have assessed penalties based on <GS19> and potentially <G19>. Remember that merely being present under the red center goal is not sufficient to be declared as blocking access. The determination of blocking access would come when the red robot attempts to access the center goal.

      Teams playing aggressive defense should make sure that they understand a couple of rules; <G9> Strategies aimed at damage/destruction/tipping/entanglement, <G10> pinning/trapping, <G19> flagrant and/or repeated violation of game rules


      • Scoring into Opposing Alliance Goals

        Originally posted by FTC5873
        If, say, the blue alliance makes no attempt to score a ball in the blue Center Goal during End Game, can a red robot score in the blue Center Goal without penalty, or would this be a penalty under <GS18>?

        A: There is nothing in the rules that prohibits scoring into Opposing Alliance Goals (Rolling or Center), as long as no other rules are violated.


        • Defensive Contact During End Game Center Goal Scoring

          Originally posted by FTC5873
          During the End Game, if a robot is trying to Score on its own alliance's Center Goal, can a robot on the opposing alliance deliberately contact the robot in an attempt to prevent the scoring, or would this be a penalty under <GS18>? I'm thinking in particular of cases where, after contact, the robot which is trying to Score is still placed in front of its Center Goal but has been jostled and is at an angle that prevents it from scoring. Note there may be penalties under <G9> which would be evaluated separately.

          A: The contact described would not be sufficient to be considered blocking access to the Center Goal. You are correct that <G9> and possibly <G10> may apply if in the opinion of the referees that there is either a strategy to damage the scoring robot or that pinning is taking place.


          • Incidental Tube Contact &amp; GS8

            Originally posted by FTC8579
            With all of the recent forum posts concerning GS8 and GS9, it seems a lot of new interpretations of the rules are coming into play based upon how various people are reading the responses and there seems to be a lot of confusion regarding what exactly will or will not count as a penalty.

            Our primary interest is with GS8, so I'll frame my questions based upon that one.

            With the wording "robots may grab onto their own Alliance's Rolling Goal in any location except for the Ball Tube", it' is our understanding that it's perfectly legal to us a hook to catch onto the lip of the rolling goal base - I don't think there's any question there. The statement of "robots that grab their Rolling Goals by the Ball Tube will incur a <penalties details...>" is very clear about a penalty for actually grabbing the tube - no question against that and our robot never wraps anything even partially around the tube.

            Our question is in the various interpretations of the phrase "incidental contact with the Ball Tube during Scoring or pushing is allowed" and the recent forum addition of the term "intentional" (which makes no appearance in the original rules). Here is what type of contact our robot makes with the ball tube. Can you clarify which is legal and which is not?

            1) While dragging the rolling goal around the field, the tube is generally 1/4" from the back of the robot. When making turns, however, the tube will come in contact with the back frame of the robot. When the robot straightens and continues forward, or turns the opposite direction, the robot will then pull back away from the tube.
            2) While dragging the rolling goal around the field, if the robot is run in reverse, the back of the robot touches the ball tube. Running the robot forward again will remove contact from the ball tube and leave a 1/4" gap between the robot and ball tube if the hook is attached to the rolling goal base, otherwise, it'll simply drive away from the rolling goal.
            3) While operating a lift to deliver the balls into the top of the rolling goal, the lift will brush against the ball tube (not for control or alignment purposes) as it is rising.
            4) When the lift mechanism is above the goal and releases the balls, sometimes the lift may hang over the ball tube by 1/4" or less. When the lift mechanism comes back down, it may touch the top of the ball tube, but the mechanism will tilt forward and get pushed out of the way by the ball tube - not actually snagging on it.

            Per the original rules of "incidental contact with the Ball Tube during Scoring or pushing is allowed", it would seem to me that all of these would be permissible, yet it seems that the addition of the "intentional" phrase challenges this understanding.



            A: It is not possible for us to rule on all possible scenarios of contact between a robot and a Ball Tube.

            In general, the referees are looking to verify that observed contact was incidental and inconsequential. Both must be true for the referees to not issue a penalty. Contact that is of long duration, always happens or is intentional should be deemed not incidental. Contact that is beneficial or aids the robot in control or scoring should be deemed not inconsequential.


            • Resting Mechanism on Rim of Ball Tube

              Originally posted by FTC5069
              During the autonomous period and/or during teleop, is the robot allowed to touch/rest on the rim of any given tube when scoring balls? Over the course of many matches, we have observed robots that lines up to the respective tube and then touches the rim of the center goal or rolling goal tube with a mechanism that is used to empty their cache of balls. Is this considered a penalty or is this considered to be incidental even though these mechanisms constantly touch the rim of the tube? Thank you.

              A: Contact with Ball Tubes that is deemed by the referees to be either intentional (not incidental) or beneficial (not inconsequential) should result in penalties being assessed based on the appropriate rules. Resting a mechanism on the rim of a Ball Tube is one example of contact that would likely be deemed as a violation of <GS8>


              • Defense against opposing ramp

                Originally posted by FTC8593
                Assume that Driver Control Period has begun and the alliance's robot has already drove off the ramp and has clear access to its rolling goals.

                According to the section 1.4.3, the only points that can only be scored during this phase is by "collecting balls and placing them in the rolling goals". However we know from games that many alliance will use this time to have one robot push their rolling goals onto the ramp for 30 points apiece. Technically this scoring opportunity only is mentioned in the End Game rules (1.4.4) but is perfectly legal during the driver controlled period (as verified from forum posts).

                Given this technicality, may an opposing alliance team simply park in front of the ramp for that 90 seconds before the End Game? It is not actually blocking access to scoring and doesn't break GS17 or GS18 which only apply to the End Game.

                A: Robots that prevent an opposing alliance robot from accessing the ramp are potentially in violation of <G10> based on the definition of trapping ... "preventing an opposing alliance robot from accessing or escaping from a constrained area of the playing field for an extended period of time". Robots should expect to received penalties based on <G10> if they prevent access for extended periods of time (1st penalty after 5 seconds. additional penalties each additional 5 seconds)
                Last edited by Pierluigi Collina; 12-22-2014, 02:24 PM.


                • Game Rules and Game Play - Answer Thread

                  Originally posted by FTC8221
                  What is the official ruling for penalties when a robot delibritly touches/grabs a goal tube, or accidentally touches/comes in contact with the goal tube?

                  A: Please see rules <GS8> and <GS9>.


                  • Game Rules and Game Play - Answer Thread

                    Originally posted by FTC8593
                    Our team has a ball chute on a lift that they raise over the rolling goals and drop into the rolling goals.

                    They realized in their first tournament that from a poor angle 10-15 feet away, it is difficult to visually judge whether the scoop is actually aligned over the tubes which often resulting in a miss.

                    So the kids came up with attaching 4" hanging string to the bottom of the ball chutes lip (they call it the goatee). It is simply a visual cue to see if they are aligned over the tubes but occasionally depending on how high they raise the lift this piece of string will touch the tubes.

                    Is this possible touching legal?

                    A: If the referees determine that the contact was purposeful (i.e. not incidental) or beneficial (i.e. not inconsequential) they will assess penalties based on <GS8>. It is likely that the string deflecting upon contact with the ball tube will be seen as beneficial (i.e. aided alignment)


                    • Originally posted by FTC9387
                      During a recent match, a robot moved in front of the opposing alliances ramp in order to align themselves with the center goal. While they were backing up, the beginning of end game sounded. That robot immediately pulled forward out of the way of the ramp. No robot to robot contact was made. The robot was never in one of the restricted parking zones. Would the robot be guilty of violating either <G10> or <GS16>? Thanks.

                      A: As long as the robot stayed clear of the Keep Out Zone and, in the opinion of the referees observing the match, did not prevent an Opposing Alliance robot from accessing the Ramp/Platform, it has not violated either <G10> or <GS16>. The trapping aspect of <G10> and the Blocking Access aspect of <GS16> both require interaction between opposing alliance robots.


                      • Dead Robots

                        Originally posted by FTC3785
                        At a recent event, a red robot falls over and ends up blocking the blue ramp. The red robot "tip over" was "without malice" but as the ramp is now inaccessible- to the blue team. Is this a blocking access penalty or is this an example of the "dead robot" exception.

                        A: As was stated earlier, dead robots are in general not assessed with penalties. If in the opinion of the referees, the robot was intentionally tipped over, it is likely that <G19> consequences would apply, in addition to violations based on <GS19>.


                        • Balls Trapped within a Robot

                          Originally posted by FTC5069
                          As a follow-up to posting #146, if during Autonomous a robot is positioned near the center goal and 10 or more balls fall onto/into the robot caused by the cascade of balls being released by another robot, is the team considered to be controlling those 10 balls? Would they be assessed a penalty for those balls that fell into their robot during the autonomous that they can't get out? Would the penalty be assessed every 5 seconds? Thank you.

                          A: Unless balls are placed in to a robot intentionally by an opposing alliance robot, the robot is responsible for all balls that become trapped within the robot. In this situation, the robot would likely be assessed multiple <GS1> penalties depending upon the duration of the violation.


                          • Autonomous Goals in Parking Zone

                            Originally posted by FTC6022
                            If an autonomous goal is partially placed in a parking zone, (such as breaking past the tape line and partially entering the zone, for example,) does it still count as parked?

                            A: Yes. When it breaks the tape line, it is considered "In" the Parking Zone - which is the requirement for scoring at the end of the Autonomous period.


                            • Mirror to reflect IR Beacon

                              Originally posted by FTC4150
                              Is it legal for a team to have a concave mirror mounted on their Robot, and sit on the top of the ramp in Autonomous and aim this mirror in an effort to reflect the IR Beacons Signals from their IR Beacon to the other side of the field, as a defensive strategy , to intentionally confuse the other Alliances Robots in any attempt to use their own IR Beacon Signals?

                              A: No, this is not a legal strategy and is not in the spirit of the FIRST Tech Challenge. The mirror would violate <R12> (interferes with other robots). Rule <G19> could also be called against the team that does this (which could be an infraction that leads to a disqualification).
                              Last edited by Pierluigi Collina; 01-07-2015, 11:57 AM. Reason: add title


                              • Intentional rotation of center goal

                                Originally posted by FTC5062
                                Hello, our question is about the end game. On 9-17-2014, post #3, was about moving the center; our question is about rotating it.

                                At a league play event, a red robot was able to slightly rotate the field center enough that the blue robot missed the high goal. The red robot pushed on it's own end of the center (from the side) so it was not blocking access of the blue robot from it's goal <GS18>. Does this violate any rule that would cause a penalty to be assessed?

                                The referees held a discussion at the end of the match and only warned the red team that it was possibly a violation of <G19>. I know you can't comment about the referees' decision, however, is this a "legal" way to stop a team scoring?

                                Thank you.

                                A: Intentional rotation of the center structure would be considered field damage and should be penalized based on <G9>, with repeated violations potentially trigger <G19> consequences.