The play area is a grid, hitting any tile with a Sword or Spartan Laser will turn it red and change its physics to "Normal", dislodging that tile and allowing it to fall away. After the initial 20 seconds, the outer edges of the grid will fall away on their own once every 10 seconds.
Eliminate the enemy by destroying the grid below their feet and making them fall to their death.
Use custom game types:
Higher Ground by Dual Universe, or
Higher Ground: Teams by Dual Universe