We recently had our Australian Championships for RoboCup Junior. One of the divisions I'm heavily involved with is the rescue league. The robots need to navigate the maze of tiles to get to the 'chemical spill' (large green area). Once there, they need to 'rescue' the victim. (juniors just push it out, seniors have to lift it onto a platform).
The maze itself consists of a sequence of tiles, which are revealed to the participants just before each round. The sequence changes for each round and generally gets harder as the rounds go on. Plenty of NXT robots as well as RCX versions and a few hybrids and custom built robots.
This video was taken by one of our student referee helper over the two days.