One command - UHC BOX

Ultra HardCore, or UHC, is a very popular minigame. Most of you have probably seen it at least once, and want to play it with your friends as well. Now, you can simply set up your own server (see the official Minecraft website), paste this command in a commandblock, and have fun. You can choose your own seed, players and rules.
This is what it does:

-You stop regenerating health (duh)
-You can choose from six teams
-The teams get spread over a 2,560,000 squared meter area
-That area is reduced to 160,000 squared meter in one and a half hours.
-Every 20 min you get a notification.
-The mid-point of the map is always 0,0.
-If you die, you get set in spectatormode, away from the game. (You should just leave the server then)

Tips:
-Place the command block at least 800 blocks from 0,0 so the structure isn't accesable whilst playing.
-Make sure everyone is in a team before starting the game.
-You an experiment with the amount of tems and the team sizes. You can also use some of the six teams, or play FFA.
-Make sure you have a good seed before playing. A map that is half ocean is no fun.
-Ban strenght 2 and regeneration potions for a more fair game.

Enjoy!