Official designation: M9 High-Explosive Dual Purpose (HE-DP) Fragmentation Grenade
Damage: High
Range: Long
Ammunition (Additional): 4 Grenades
The Frag Grenade is the primary anti-infantry grenade issued to UNSC Marines. The secret behind its destructive power is the fact that it uses only a tiny amount of high explosive. This blast propels shrapnel everywhere, seriously wounding or killing any unit in the blast radius. It is an anti-personnel weapon that can introduce chaos and carnage to even the most well-drilled group of infantry, and is also effective against vehicles. When thrown, its timer begins on first impact with a surface; detonation follows 0.5 - 2 seconds afterwards. This feature makes it ideal for disrupting (or eliminating) well-armed or entrenched enemies from a position of relative safety. If you aim it at a wall, you can judge its bounce to drop it in the desired spot.
The Frag Grenade isn't as effective against shielded or especially hardy foes as it ideally could be - think Elites, Brutes and Hunters - so you should use a couple when facing strong enemies. A good tactic is to soften up a few assailants with a grenade, then follow up with a burst of automatic fire. It can also be deployed on the ground to facilitate a hasty retreat. Try throwing one while backpedaling or before turning to run. Following enemies will be in for a rather nasty surprise or, alternatively, simply deterred from giving chase.
The frag grenade has significantly more bounce and significantly less splash damage than it did in the first Halo title. Contrary to the beliefs of some gamers, in multiplayer, a kill from a single frag grenade does not occur when a player's shields are fully charged. A frag grenade does have the ability to kill a player when his or her shields are in the process of recharging, which can lead to this illusion, especially when there is a several second gap bewteen recieving damage from a firefight and being killed by the grenade. However, the grenade will generally only eliminate the opponents shields, providing they are fully charged.