Telefragging

Telefragging is an unknown factor that occurs during gameplay. It is a rare occurrance and usually must be performed on purpose.

How to
The trick requires two people on any level with a teleporter. The first player must go through the teleporter and then remain standing in the exit of the teleporter. When the second person tries to go through the teleporter, they will not be able to get through, but the first player's screen will begin to go white and their controller will slowly begin to shake. Eventually their body will go sprawling away from the teleporter, and it will say player 2 has telefragged player 1. You can utilize this on Beaver Creek by instead of walking into the teleporter, very slowly walk through it and instead of being shot forward you will appear at the exit without being teleported back through. Then simply do what it says above and voila, you get a cheap telefragging kill.

Easiest to do in Halo: CE because the teleporters do not shoot you out.