Questions & Answers2021-11-22T10:24:28+01:00

Questions & Answers

At this page we will publish frequently asked and important questions related to the WRO® 2020 games. The answers on this page should be seen as additions to the rules and will be used for the WRO International Final. Be aware that in your country local competitions may follow slightly different rules. Always use the rules provided by your National Organizer.

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Senior: 2nd-Day-Challenge: The table with scores for Senior lists 220 points total, but if you sum up the points, you get 240. What is correct?2021-11-19T23:03:27+01:00

The total points are 240. The table lists a wrong number of points.

2nd-Day-Challenge: Is it allowed to use a hard-coded solution for the 2nd-Day-Challenge?2021-11-19T16:57:06+01:00

Yes, you can use hard-coded solutions, because there is no randomization in the 2nd-Day-Challenge.

2nd Day Challenge: What is the time limit for this run?2021-11-19T15:33:54+01:00

The time limit is the same as for the normal challenge: 2 minutes (120 seconds.)

2nd-Day-Challenge: Do teams have to solve the mission in the presented order?2021-11-19T14:56:18+01:00

No, you can solve the mission in any order you want.

Junior: 2nd Day Challenge: Do the pillars have to be in an upright position?2021-11-19T14:57:37+01:00

No, they can lie on the mat as well.

2nd Day Challenge: Where does the robot have to start and end its run?2021-11-19T14:39:08+01:00

The robot has to start in the starting area as in a normal run. It can finish its run as soon as the last mission has been solved. It does not matter where the robot is stopping.

If the table is a little bit bigger than the mat, what happens to elements, that touch the gap.2021-11-18T17:55:48+01:00

If there is a gap between the mat and the table, the areas at the edge of the mat will be extended to the border of the table. Objects, that touch the gap will count as inside of the area. For example in senior energy units, that touch the gap next to a house will be counted as inside the house (compare picture).

IMG 20211118 163454
International Final: Can teams use different robots for the two normal runs and for the 2nd-Day-Challenge?2021-11-17T11:53:41+01:00

Teams can modify their robots during the 48 hour of the competition as much as they want.
A differently constructed robot in different videos of one team is allowed.

Is it allowed to remove surprise rule objects, if the team does not want to solve the surprise rule?2021-11-15T09:21:12+01:00

Yes, surprise rule objects can be removed before the run if the team does not want to solve the surprise rule.

UPDATED: How do you control that no hard-coded solutions are used in the online international final?2021-10-27T09:06:07+02:00

The general rules state that no data input into the robot is allowed after team handed it in (Rule 6). The aim of this rule is to change the randomization after the robot has been handed it, so no hard-coded solution are used to solve the task.

In the online international final, this rule is interpreted as follows: No hard-coded solutions are allowed. It must be clearly visible in the uploaded video, that the robot uses its sensors to solve the randomized task.
In lack of clarity, a head judge will contact the team separately for a specific presentation of the code and the robot. Non-compliance to this interpretation results in deduction of points or disqualification.

Update (27-10-21)
Following the rules some part of the randomization are valid for the whole competition day (Elementary: position of barriers; Junior: position of parked cars). These elements will have the same position in all 5 randomizations for the international final and can be hard coded into the robots. There is no need to detect these objects via sensor.

In the online international final, the robot size is controlled by the robot fitting in the start area. However, the area is only 24,7 x 24,7 cm. How does this work?2021-10-22T08:36:23+02:00

For the online international final, the black line surrounding the start area belongs to it. Therefore, the start area is big enough for the robot.

Can the robot move barriers/fences and put them back in the right place?2021-08-20T15:19:51+02:00

“not moved or damaged” in the scoring table means: at the end of the run the barrier/fence is in the starting position

In WRO it is always the end-situation that is scored. This means that the robot can lift or move any barrier or fence during the run and then put it back.


How should the solar cell be placed on the robot at the start of the run?2021-08-20T15:20:27+02:00

“There is one solar cell that should be placed on the robot at the start of the run.”

What does this mean?

  • The team can choose how the robot brings the solar cell to the correct area.
  • They can put the cell on the robot, under the robot, in front of the robot or in any other position touching the robot.
  • They can even put the cell inside of the robot, but only if this does not delay the starting process.
    Meaning: During the start process they cannot remove pieces of LEGO from their robot, put the panel in and then put the pieces back.
  • The team cannot touch the solar cell anymore after the start.
  • Whatever option they choose: the solar cell cannot stick out of the start area.
    Meaning the projection of the cell and the robot need to be inside the start area.


Junior: 2nd Day Challenge: Do the pillars have to be in an upright position?2021-11-19T14:57:37+01:00

No, they can lie on the mat as well.


The wind turbine has fallen over but still only touches the relevant area.2021-08-20T15:23:56+02:00

The wind turbine could have fallen over during the run (is on its side) but still be only touching the relevant area.

In this case the wind turbine would count as ‘not moved or damaged’, because not moved in WRO means that it is still inside the designated area in the end situation.

The team is lucky and will get the bonus points.

When are Energy Units completely in house or storage battery?2021-08-20T15:23:15+02:00

Unfortunately there is an error in the calculation of one of the examples. This can lead to confusion.

An Energy Unit is completely in the house or storage battery if it only touches the area (= the field).

Units that are on top of another unit, or that are in any way supported by another unit or the fence of the storage battery will get no points.

See the corrected example for the house. (24 instead of 44 points.) And the extra example added. (Only points for the yellow unit in this case.)

To avoid further confusion:
“only touching” refers to how the unit is supported. It is OK if units that are fully supported by the field are just touching each other because they are next to each other.

wrong calculation


What is meant with: “the omni wheel components of a single wheel must be on one position on an axle”?2021-08-20T15:25:44+02:00

This means that the wheel cannot be devided over both sides of the motor.

See image for clarification.

How many wheels can I use?2021-08-20T15:24:37+02:00

Rule 8.9 for Football can cause some confusion, because it specifically mentions omni wheels.
It was written this way because almost all robot designs use omni wheels. But the intention of the rule is that each robot can have a maximum of three driven wheels in total.

Therefore the rule should be read as follows:

8.9 A maximum of three driven wheels – built of only LEGO branded components – can be used on a single robot. Use of a reciprocating kicker in the remaining EV3 output port is strongly recommended.

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Future Engineers

The rules says that the color of the red sign has the following color “PANTONE 1795 C, RGB (238, 39, 55)” but RGB (238, 39, 55) does not corresponds to PANTONE 1795 C. Which color is correct?2021-08-20T15:30:31+02:00

The actual difference of these two colors is insignificant for the camera because the data get from the camera will really depends on the ambient light conditions. But in order to get rid of ambiguity in the rule statement, the recommended color is RGB (238, 39, 55).

Is it possible to prepare lesser number of red and green parallelepipeds rather than stated in the section 8.3?2021-08-20T15:29:57+02:00

Correct. Although the section 8.3 states that 8 red and 8 green signs must be prepared in advance to keep needs of the drawing procedure for the final round, actually, 5 red and 5 green parallelepipeds are enough – there will be no such variant of the colored objects combination that requires more than 5 objects of the same color.

Is it allowed to use two motors connected to one axel on the vehicle (it is not a differentiated wheelbase)?2021-08-20T15:29:27+02:00

The paragraph 9.2.3 of the rules says “the vehicle must be a 4 wheeled vehicle with one driving motor and one steering actuator of any type.”. So, if two motors connected to one axel are for driving, it is not allowed. If this approach is used by somehow for steering purposes, it could be considered as a steering actuator.

It seems that the sizes were not updated in the table of the “Appendix B. Game field for national/regional finals”, doesn’t it?2021-08-20T15:29:00+02:00

Yes, the proper table must look like the following, see photo.

Will the number of teams be reduced in the WRO 2021 International Final after the qualification round?2021-08-20T15:27:50+02:00

In general, the qualification round could be used to reduce the number of teams participating in the competition. But since WRO Future Engineers is the pilot in the season 2021, the qualification round will be used to allow teams get more points.

Should the match be stopped if the vehicle touches the sign?2021-08-20T15:27:13+02:00

As soon as the sign is pushed completely by the vehicle from the circle it is located initially the match will be stopped.