Grenade sniping
From Halopedia, the Halo wiki
Nade Sniping is a trick done in Halo: Combat Evolved. Have Infinite Grenades and go to a level like Longest and climb up a ladder to a ledge. Then keep chucking Grenades everywhere nonstop. This makes you a hard target to get to, unless another player has a sniper rifle or other long range weapon.
