It says expansion is limited to 22 inches, including diagonal dimensions.
If a robot is an 18x18 square it’s diagonal dimension is already more than 22 inches.
is it maybe supposed to be 32 inches?
1 Like
You are correct that by the current mainstream interpretation of the rules, a robot that is 18” by 18” would be illegal.
Once the official Q&A system opens, we’ll be able to verify that it is the correct interpretation, and the GDC might change the current rule in one of the many game manual updates that will happen this year.
1 Like
There is a discussion about this now, but I think the GDC just worded it wrong. Of course the GDC wouldn’t restrict the usual 18x18in robots, most likely they just wanted to limit expansion like how in Over Under.
4 Likes
I am inclined to believe that they intentionally made 18x18 bots illegal, especially since Rule SG2b explicitly mentions “diagonals” and “any two points of the Robot”:
This limit refers to the horizontal distance measured between any two points of the Robot, including diagonals, relative to the playing Field (i.e., it does not rotate with the Robot)
Fun thing to try out: go to Desmos and graph these 3 equations:
sqrt(x^2 + y^2) < 22
-18 < x < 18
-18 < y < 18
The area that’s covered by all three of these equations shows the legal starting configurations under the current rules!
Here is the correct equation: \sqrt{(x^{2}+y^{2})}<11\left{-9<x<9\right}\left{-9<y<9\right} (simple math error)
(The black lines are 12.5 or 25 hole lengths)
They are definitely pushing for fewer cube designs and more holonomic drives.
4 Likes
But the relative to the field bit is really weird, how is it neccessary when saying all diagonals
The limit isn’t 11 inches diagonal / 9 inches X & Y, it is double that (22in diagonal,18 in X, Y). What are the equations listed here trying to show?
I believe it mentions “relative to the playing Field” to clarify that it’s illegal if your robot intentionally rotates to an out-of-size position relative to the field (while still maintaining 22" diagonal when it’s the right side up).
Otherwise, you could build a robot that technically has a 22" diagonal when its in its starting position, but then intentionally slightly tip it forwards/backwards (which is out of size relative to the field) while still maintaining the 22" diagonal from the robot’s perspective.
I understand what you’re saying, but you’re confusing absolute and center distance. Your math implies, the starting size is 36x36 because the points (-18,0) and (18,0) are 36 units or inches apart. Then, for the diagonals, you’re confusing radius with the diameter, the formula for a circle is (x-h)^2+(y-k)^2=r^2; where the center is (h,k) and r is the radius or 1/2 diameter. Hope this helps 
1 Like
The GDC have said they will be addressing the expansion issue.
(They mentioned it i their forum post today)
I suspect the fix for this will be in the first manual update of the season, and thus it seems likely the 15x15 will not be correct.
7 Likes
Yes, most likely the box will be 22x22 and rotate with the robot. Thereby allowing 4 inch or 8 pitch expansion in both x and y.