Robot Tipping

One major event that I have noticed occurring a lot in OU matches are robots being tipped on their back, or sides, or completely flipping. I have seen this happen in matches I have been a part of as well as many matches I have watched on YouTube. With many over-under, robot designs have a poor center of gravity due to things such as lifts, blockers, and other things extending upward, along with many designs having sleds to climb the black barriers with. Both of these designs seem to cause tipping when regular defense is encountered since the sleds or protruding wheels can cause robots to drive themselves onto other robots off of the ground, and poor center of gravity allows them to tip easily when they are off the ground just a few inches.

According to rule G13 defense is allowed as long as there is no intent to damage or flip/tip other robots. Most of these encounters that I have seen have been through regular legal defense which turns into back-and-forth pushing usually resulting in the robot with poor COG and sled designs getting tipped. The referee rulings on these encounters seem to be very inconsistent varying from ref to ref. Going back to rule G13 section C it says “A Team should design its Robot such that it is not easily tipped over or damaged by minor contact” The key phrase here is minor contact. Most of these interactions that lead to tipping are commonly pushing and shoving from people trying to push triballs, creating space to matchload or defend teams from scoring. There is no definition of minor contact in the Game Manuel but from what I can tell these would classify as minor contact.

Having a high/poor center of gravity and having sleds on a team’s robot are design choices, not to say that are bad design choices, but teams should be aware of them when they are playing the match and encounter minor contact like pushing and shoving. Since their design allows their robot to be easily tipped, I would assume a team should be responsible for their robot being tipped if they encounter minor contact such as rule G13 sections 3 states.

The referee rulings are why I am asking this in the forum. Like I said earlier these calls have been varying from ref to ref. Some refs don’t call any sort of DQ on the robot that was pushing the flipped robot, some cite a G13 section A violation saying the team that was pushing the robot intentionally flipped them over since they were pushing them which caused them to tip. Obviously designs like wedges or forks which get under robots and flip them over would be an obvious violation of this rule. But most of the encounters I have seen have been between a robot WITH OUT sleds/forks/wedges or any sort of design that lifts a robot on top of them or off the ground, pushing a robot WITH sleds/poor COG which eventually drive themselves onto a robot or cause their opponents to drive under them leading to them then be tipped. To go with that rule G14 states that offensive robots get the benefit of the doubt, however, in some cases, it is not clear what robot is offensive or defensive when both robots are just pushing each other back and forth.

Is there a rule I am missing? If not could VEX/GDC please clarify these rules as to whether or not design choices such as sleds and high center of gravity which cause a bot to tip with minor contact are legal actions or DQs for the team that unintentionally tipped them?

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Ask the Official Q&A on for official rules clarifications from the GDC… What you will get here are caring opinions and perspectives.


Yes, but no. There are 2 answered Q&As that have clarified this gray area. My consensus is that intentional tipping to gain an advantage in the match is a violation. Although, some incidental tipping is going to happen, as over under is a very physical game. I hope this helps!

Here are the Q&As.

The Q and A answers seem to cover the fact that it is up to referees to determine weather the tipping was intentional or incidental, what I am trying to find out is what plays a factor into incidental tipping. Since many robot designs can be easily tipped do these designs which cause incidental tipping fall into the G13 section C category or is it considered a G13 violation if a team is tipped due to their design and incidental actions since I have seen it ruled both ways.