[Borobo]

I've got 2 suggestions
1) rectangular boxes about 1' high by 2' long by 1' wide that weight about 25 lbs. Robots have to pickup boxes and stack them in one of 2 sectors of the field,(which is flat), these being a protected area on you side of the field, and the other being anywhere else, where stacks can be dismantled by opponents. the scoring per stacked box is different for the sectors. possible endgame, there are 2 ramps, you get more points if you drive onto crates stacked next to the ramps, the scoring going something like 5x the number of crates high you are. ex. 3 feet high, 15 points per robot.
2) field filled with tiny balls, like the size of ping pong balls. mixed in, with something like a ratio of 20:1, are some other larger balls like racquette balls. at each end of the field is a stepped series of 3 platforms each perhaps 8 inches high and each with a bin on it. these correspond to 1, 2, or 3 points. the thing is, only the RB's actually score points. teams, therefore need to choose between dumping huge volumes of balls quickly and filling the bins inefficiently and dumping RB's only/mostly and more slowly filling the bins but scoring more points. I don't know what the endgame would be yet.