Knocking Over Opponent's Stack by Hitting Wall

Is there anywhere in the rules that will disqualify a team for directly causing the opponent alliance’s stack to fall over by ramming into a wall? I saw this strategy used in one of the VRC events in China.

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There is no rule against ramming into a wall to cause an opponent’s stack to fall over. “Directly” is an interesting word to use here because that is not direct at all. You would be shaking the wall, which could indirectly knock over an opponent’s stack.

However, that’s not what happened in the video. The team who bumped the wall was not doing so strategically, only grabbing a cube. Around the same time, another team’s stack fell over.

So while there is no rule against this, it will most likely never occur.


My use of the word “directly” may have been a poor choice. If a team intentionally rammed into a wall to knock over an opponent’s stack would that likely lead to a DQ?

If the stack falls, potentially depending on the circumstances (for example if the team had already been in the protected zone or interfering with an opponent).

If the stack doesn’t fall, no.

The video clip linked above and the wording of < SG3, part F >

Cause Scored Cubes within the opponent’s Protected Zone to no longer meet the definition of Scored

led me to believe that this is a DQ, if the “robot that slammed into the wall caused their opponents‘ stack to fall” story is true.
However, I do agree with @2775Josh that it (most likely) was that the ramming into the wall just happened to occur at the same times as the stack falling, which would not be a DQ
And, of course, aslong as the stack does not fall, it’s not a DQ for all I know.


What if a robot intentionally caused the opponent’s stack in the goal zone not in the protected zone to fall over?

That would be falling under < SG3, part B >, which reads

Contact any Scored Cubes in either of opposing Alliance’s Goal Zones

However, this does not result in an auto-DQ like parts E-G. The consequence for violating part B reads

Minor violations of points A, B, C, or D that do not affect the Match will result in 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.

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But the robot would not be physically contacting the cubes, the shaking of the wall would cause the stack to become unstable and fall over. The only thing the robot would be physically touching is the wall.

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My bad, I forgot that we were still on the shaking the wall scenario.
I couldn’t find a rule pertaining to whether it’s a DQ or not, so I don’t believe that it would be penalized. The closest thing I could find was < SG6 >, which I assume will not penalize it, unless a violation of that rule is intended.

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There have been relevant Q&A rulings dealing with similar situations. For example, this Q&A ruled that shaking the wall would be counted as indirectly contacting the stacks.

If you are saying the resonance would cause the stacks to fall over, I would probably give a verbal warning, and then an < S1> so you don’t damage my Field Perimeter, because intentionally ramming into the Field Perimeter repeatedly could be unsafe and cause damage.


That’s the illusion…
No actually
Think about it.
In the ms finals one team rushed over to the other side (when the other color was scoring), and “grabbed a cube”.

It is a reasonable idea however very few chances a stack will be close enough to make it work. Also remember hitting a field wall that hard could cause damage to the field an offense that is a disqualification. Also you won’t be able to do this on a drive station was as repeat attempts could lure referees into seeing a safety hazard. Remember referees have rule to call anything to safety.

Yes. There is nothing hard to believe about grabbing a cube in a game about grabbing cubes.


They rushed to the other side when there were a plethora of cubes accessible to them.

“Plethora” is an interesting word to use here.
In fact, there were no other cubes on the field at the time this occurred.


I see your point, but it didnt have to involve them running into the wall. Nevertheless, this is a tactic we’ve seen in the other china finals, and it seems valid.

I interpreted the situation very differently actually.

1:54min - the robot bang against the wall to collect the cube and reverse away from the wall.

Meanwhile the other robot was trying to stack.
1:56min - the robot moved off from the goal and the stack fell at the same time.

There was a 2sec interval between the robot that hit the wall and the scoring robot moving off the goal.

It is difficult to pinpoint the falling of the stack due to the opposing robot hitting the wall.
I will put it as the scoring robot not able to put the stack into the goal properly.


That’s what I see as well - which would mean that even if the robot hitting the wall indirectly affected the stack, the stack wasn’t considered scored at the time (since the other robot was still touching it) and therefore there was no issue.

My thoughts:

  • clearly indirect (not direct), if anything
  • doesn’t look intentional at all (they are working to get a cube, not to knock down a tower)
  • there were no other accessible cubes visible in that area
  • running into the wall to grab the cube quickly doesn’t seem unreasonable (any more than running into the wall to auto-straighten). Hard to tell if abnormal force was used, but it didn’t seem so to me…
  • other robot appeared to still be touching stack, making it unscored when action occurred

Because a lot of bots are using a flip out tray would it be legal to bump into the bot at the exposed part of the tray when they are outside the protective zone?

Actually there is a rule against ramming into the wall to cause an opponents stack to fall over, the opening statement of rule states:

Stay away from your opponent’s protected areas. Robots may not intentionally or accidentally, directly or indirectly, perform the following actions:

The causing cubes to no longer be scored, does NOT have to be the result of a direct action or even intentional.