Roborally.com

Yes. Goo prevents a robot from moving out of the goo square until the goo is destroyed. However, goo does not prevent a portal from transporting a robot to a different hex. So if your robot moves onto a goo/portal square, it is transported to the corresponding portal square just like normal. However, if your robot is transported to a goo/portal square, it cannot move out until the goo has been destroyed. [Since Goo cannot be dropped on teleporters, it should be prohibited from being dropped on portals too. Then the hoops being jumped through in this answer could be avoided. --JHJ]