Sniping Yourself
From Halopedia, the Halo wiki
Sniping Yourself is an odd but fun little trick to do with Sniper Rifles, Beam Rifles, and a Covenant Wraith or a UNSC Scorpion Tank which only works on Halo 2.
Required Equipment
Walkthrough
First set your weapons as Sniping weapons. Make sure that you chose a map that holds a tank (Zanzibar, Coagulation, etc.). Second, go up to the tank and make sure you're facing the tank. Shoot your Sniper Rifle/Beam Rifle. It should reflect off and hit you. Sometimes you will die within one hit and your shield will fully go down, which would have been a headshot that deflected off the Scorpion or Wraith.
Turf method
On Turf you can do this another way. Stand with a Beam Rifle in the corner of the closed doorway behind the human medical tent. Look up and you'll see two small lamps. Shoot one of these. The shot will now jump around on the walls and eventually hit you. This may take a few tries, but after a while you can make it.
