Literally Unbeatable Change Up Strategy (As The Manual Stands)

Hi everyone,

Haven’t posted here recently, you may or may not remember me. I just looked at the new game and I realized that there is no expansion limit. So, without an expansion limit (which surely must be added), here is how you win every game against standard offensive opponents, with a standard offensive robot on your side. Obviously if both sides do this, it’s about who does it better.


In the above image, purple arrows denote actions taken in autonomous, and yellow arrows represent actions taken immediately in opcontrol. The idea is to have high torque bases on the far towers that can push through anything and make it basically impossible for any standard robots to score in the side towers. You can add a deploying screen to block the top of the tower, though that sounds difficult and unnecessary to me. The center base will have a cap that covers the top of the tower and a wall that blocks the bottom of the tower. You can actually score the ball by driving backward, as shown by the yellow arrow. This may need to be adjusted depending on the GDC’s interpretation of G16, but hey, I’m not here to design every detail of your robot for you. This is just one prototype idea. My point is: some type of a wallbot will be a dominant force in eliminations as the rules currently stand.

But you’re telling me, “Hey Aponthis, doesn’t this seem unrealistic? Wallbots never work.”

If there is no revision to the game manual, I look forward to seeing the duel of the wallbots!


You could also just have a wallbot of the kind that just has a scissor mechanism on both sides and expands outward, then park that right in front of the central row of towers.


That would be my ideal strategy if there was no auton line. With the current auton line, I would be worried about opposing robots blocks your scissor expansion (and if they get in the way of it, you could be DQed for potential damage). That’s why I think it’s important to just have high torque bases on the end to muscle your way past.

you’re forgetting something: g12 does not extend to wallbots, and the offensive robot is always given the benefit of the doubt.


Agreed. Though it is still possible if you could expand fast enough, but I’m not sure how fast a wallbot could realistically be expected to expand.

You forget the possession rule. If you wall off half the field, then you’re walling off more than 3 of your opponents balls

Edit: if this is accidentally done by a wallbot and there is no way to retract the wall, you will probably be disqualified


If someone brings this, I’ll be concerned.

(The black one is mine. :slight_smile:)
Otherwise, defensive bots have been doing fine for as long as I can remember.

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There’s also this, which would definitely incine many teams to not react so mercifully to a wallbot. Rulings in this situation will tend to go toward the offensive bot (per G13) so a wallbot would definitely need to be able to take a ramming


Also, it says that Change Up is intended to be an offensive game, so defense strats, while legal, are a little bit

Let’s go into the rules:

Possession – A Robot is considered to be Possession a Ball if a Ball is in an unscored position and
either of the following criteria are met:
• The Robot is carrying, holding or controlling the movement of a Ball such that if the Robot changes direction, the Ball will move with the Robot. Pushing/plowing Balls is not considered Possession,
however using concave portions of your Robot to control the movement of Balls is considered
•The Robot is blocking the opposing Robot’s access to Balls that are located between Goals along
the field perimeter. Blocking access to Balls is considered Possessing those Balls only if the
opposing Robot is attempting to make contact with those Balls from close range and those Balls
are at least partially within the width of the Goals between the Goals. Robots on the same Alliance
working in tandem to block access to Balls would share the Possession of the Balls. See for
Possession limits.

The first condition would clearly not be met.
The second condition is a little less clear. But it is pretty clear that any balls on our side of the field would not be within “close range” and are unlikely to be “partially within the width of the Goals between the Goals” if I am reading it correctly.


That has literally always been in the rules and has never prevented defensive robots. I don’t know about 2012 but it was in the rules in 2014 (Toss Up, the first video).


This has always been the case. You have to build it robustly. Look at the end of the first video I posted - a robot attempted to break through 127C at the end. Just build it strongly.

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I can confirm, having built the wallbot in question, a lot of people tried to break my robot. None of them did. Short of building a robot specifically to break my robot, at which point it’s not an offensive robot, you’re not breaking three steel bases linked together with steel C channels with VEX motors. This isn’t BattleBots, the motors aren’t meant for that.


Goals are about 6’ apart, so you would need to quickly push their balls up against your wall to make it harder to rule that they were trying to access it. Need to wait on the referee training videos to get posted, but I’ll bet there is something in there about that.

Nice idea though, but it would be a once a season move, after that people would be onto you.

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If your wall stretches across the autonomous line, (from what I understand) this could be violating the possession limit

Now you can’t just go and ignore the “from close range” part. If the balls are 1 or 2 ft behind the wall, this should surely be allowed. Also, if there are one or two that are considered within close range, that is okay, just no more than 3. This isn’t a hoarding rule; they just count toward your nonzero possession limit.


You’re missing the “from close range” clause. Without seeing any referee training videos, and without clarifications, I’d rule that if the ball is a robot length away from the robot doing the blocking, it’s not “close range”. Fortunately I haven’t been a ref since college, so I don’t have to be the one to make those judgement calls when somebody inevitably builds this thing.

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Also, kind of curious how you think people would beat this even once they’re aware of it. I ran a wallbot the entire Toss Up season, we lost plenty because of bugs in the design we worked out over the course of the season, but nobody ever actually countered us. Especially with a design like this, you’d need to out torque a dedicated high torque pushbot, which would cripple you in any other game, because now you’re too slow to win.

I guess you could make a high torque variant base, but then it’s basically a one on one of your partner vs the wallbots partner, and a three base wallbot is still going to be able to annoy your partner, so I don’t love those odds.

I’ve got no horse in this race, I don’t mentor any teams, just run events and judge. Turns out I just really really miss this stage of early season strategy development.


The wall bot auto needs to move and place next to the center goal. As a defense against that, I’d do an auto to place along the auto line about 4’ from the wall. At driver control step across the line and let the wallbot close across behind.

Then just

  1. move balls to other side of the wall for your alliance partner to score.
  2. start removing balls from the goals on your side.

You are really playing 2v1 at that point, the center tower is out, and you should be able to keep balls from being in at least 2 of the 5 remaining goals.

The high traction base is also relying on the far end of the wall to be against the goal, so when people push on it, the goal anchors it. But now that you are behind it, a running start and you should be able to push it away from the goal.

Don’t know for sure but I’ll bet we see one across the season and we can compare notes then :slight_smile:

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With wallbots, if you are containing more than 3 of your opponent’s balls, you’ve violating the possession limits. Just something to keep in mind.