Contest Rule Clarifications

This page summarizes rule clarifications in question / answer format. 

Question: Am I using the right rule set document?
Answer: Make sure that the document has same revision as found as the version located on


Question: Does it cost to enter a competition?
Answer: Entry to competition events is free to DPRG members and students (at any grade level).  For others, the entry fee is $10. Anyone paying a entry fee can participate in any or all of the events of the competition.


Question: How are the “cans” used in Table Top and CanCan Soccer made?
Answer: The cans are standard 12 ounce aluminum soda cans that been prepared as described in dprg-can-design-20141202.


Question: In CanCan Soccer what goal must the can pass through for me to score?
Answer: The can must pass through your opponent’s goal, which is the opposite goal from where you started.


Question: In CanCan Soccer is my robot allowed to capture more than one can at a time? For example, store cans in a robot mounted rack?
Answer: A robot can only capture one can at a time.  If it captures more than one can, the judge will immediately remove the second can and replace it on the playing field.  In other words, only one can could be placed on the mounted rack and no other can could be captured until the possession of the first can is lost.


Question:  In CanCan Soccer can a robot defend its goal?
Answer: There is nothing in the rules that say a robot can not defend its goal. However, aggressive behavior toward your opponent is not allowed.
For example: 
  • Robot charges opposing robot and attempts to entangle it. – Not allowed
  • Robot patrols in front of its goal without locking on to the opposing robot.  – Allowed, however hitting the opposing robot, could be considered aggressive by the judge.
  • Robot sits still in front of goal and acts as an obstacle. – Allowed, however a robot that runs into it may not be considered to be aggressive. If the robot has possession of a can it also controls the reset.
  • Robot blocks or intercepts a can launched towards goal by opponent. – Allowed
Remember that who has the most cans at the end of the clock, wins.


Question:  In CanCan Soccer what does “possession” mean?
Answer: For CanCan Soccer, any can that is physically touching the robot is considered to be in that robot’s possession, unless the other robot has possession of the can first.  For example, a robot captures a can and is moving to the goal and the other robot entangles the first robot. It also touches the can that the first robot had captured. The second robot does not have possession of the can even though it is touching it, since the first robot already has possession of it.
A robot doesn’t need to possess a target can to score. If a can passes through a goal, a point goes to the robot that is using that goal to score (i.e., not the goal’s owner).  The goal that a robot starts in front of is the goal that it owns.


Question:  In CanCan Soccer who can call a “reset”?
Answer: For CanCan Soccer, the judge calls a reset. If both contestants, ask for a reset, the judge generally will call a reset. If one contestant’s robot has possession of a can, he/she can call for a reset, however, the contestant that doesn’t have a possession of a can cannot call for a reset until the possessed can is scored or it is obvious that no score is going to occur.


Question: Is it allowed in Tabletop 2 to collect all three cans, for the three regular challenges and the bonus mission?
 Answer:  Yes, the robot can collect the three cans then drop one off the table, one in the box, and take one back to home.  In the bonus mission, the robot could collect all three cans and then lay them back on the table in a line.


Question: In the challenge level line following competition when the robot finds the three way gate must the robot continue  to the end of the path that is a dead end or must it first complete the closed course loop?
 Answer: The robot must complete the closed course loop (i.e., pass the starting line again). It can explore the dead end, return,  and complete the closed course loop, but it is not required to go down the dead end.


Question: Is it allowed in Tabletop 2 to collect all three cans, for the three regular challenges and the bonus mission?
 Answer:  Yes, the robot can collect the three cans then drop one off the table, one in the box, and take one back to home.  In the bonus mission, the robot could collect all three cans and then lay them back on the table in a line.


Question:  For Can Can Soccer are the locations of the cans symmetrical between the halves of the arena?
 Answer:  The cans do not have to be symmetrical between the halves of the arena, however the setup should be fair to both contestants.


Question:  For Can Can Soccer how will the starting locations of the cans be marked on the arena floor?
 Answer:  Starting locations will be marked on the arena floor with small squares of blue painter masking tape. The tape marks will be no bigger than 3/4″ X 3/4″.


Question:  For Can Can Soccer how will the goals be assigned to competitors for a round?
 Answer:  Usually the contestants come to an agreement to where to start. If however both contestants cannot come to an agreement the judge will use a coin flip to decide which the starting goals.


Question: For Can Can Soccer, will the goals be switched during the contest to remove bias from any lighting variance?
 Answer:  In case of extreme lighting differences the contest may be divided into two periods with the goal exchanged at the judge’s discretion. In normal lighting situations, the goals will not be switched.


Question: Big Table Top 2 and Can-Can Soccer rules for the setup of the fields have markings made with “blue painter’s tape”. I’m wondering what properties that has for IR. I have simple drop off sensors  and am wondering if my robot thinks it reached the end of the world when it comes across a strip of tape?
 Answer:  The blue tape was chosen because of its availability and its low impact on IR sensors. In Big Table Top 2, the seam between the two parts of the table is covered with blue tape to prevent tripping sensors. The uncovered seam will trip some sensors. The tape used is “3M ScotchBlue  Original Multi-Use Painter’s Tape” available at Home Depot and similar locations. I would suggest obtaining some and determining how your sensors respond to going over it. The table top is white, a piece of poster board could be used as a simulated table top. The starting box in table top is marked with black electrical tape (3/4″) and it will definitely trip an IR sensor. You must determine how to leave and reenter the starting zone. The blue tape used in the Can Can Soccer contest is only to help aid placing robots and similar activities. It isn’t meant to be used as a navigational aid.


Question: Can it generally be assumed that cans are “free standing”? In other words, if an obstacle is wider than a single can, or smaller than a single can – it can’t be a can?
 Answer:  The rules for Can Can Soccer say that the cans are randomly placed. The judge places the cans just before the competition. No practice runs are made on the final can positions. The judge will mark the course with small pieces of blue painter’s tape, so that cans will be in the same location for all competitors.
Now we get to past experiences versus what is stated in the rules.
The judge generally will:
  1.  Place the cans so that they are divided equally on the two halves  of the field.
  2.  The cans are at least 2 inches apart.
  3.  The cans are set no closer than 6 inches from a wall.
However, the judge is not required to do these things.
You would be safe in saying that an obstacle smaller than a single can isn’t a can. I also think you would be safe to say an obstacle larger than 2 cans and a couple of inches isn’t a can. If an obstacle moves, it is definitely not a can.