M9 fragmentation grenade
From Halopedia, the Halo wiki
The M9 High-Explosive Dual-Purpose grenade (M9 HE-DP) is the standard-issue hand grenade of the United Nations Space Command. The weapon is semi-erroneously known as a fragmentation grenade and the colloquial frag. Furthermore, the M9 designation technically refers to several models of varying design. Like most UNSC small arms and explosives, the M9 is produced by Misriah Armory.
HE-DP stands for High-Explosive Dual-Purpose. This designation means that it is designed to be effective against infantry and lightly armored vehicles. AP FRAG can be viewed on the Halo: Combat Evolved M9's olive casing. AP designates "anti-personnel", indicating the weapon's intended use.
The grenade has a hard metal casing, with a frangible design meant to break apart into small, regular shards. This surface creates consistent, reliable fragmentation patterns for the grenade, rather than randomly rupturing along metallurgical faults. The grid-shaped casing houses a charge of ComL high-explosive fitted with a mechanical primer. When the charge detonates, it shatters the grenade's casing, sending shrapnel flying away at high velocity.
In all Halo games, the grenade must first hit the ground before exploding. In Halo: Combat Evolved, the grenade would not detonate mid-air. In Halo 2 and Halo 3, it would bounce and explode mid-air a moment after bouncing. But in Halo 3, if the grenade was thrown up, and hit a surface going up, it would not explode until it hit the ground. This is a safety feature, ensuring the grenade would only explode after striking a surface after being thrown, and not in the user's hand. This may explain the lack of a "spoon", or handle, on the Halo 2 and 3 M9 HE-DP grenades. The spoon is a device that is gripped while the grenade is being primed. It ensures the grenade will not explode until after the spoon is released, as it starts the fuse of a grenade as it flies through the air after it is thrown. In Halo: Combat Evolved, the spoon would have negated the need for this Halo 2 safety feature.
The grenade is primed with a small button located on the "handle", quite unlike modern fragmentation grenades which use a pin that must be pulled before priming.
In Halo: Combat Evolved, the fragmentation grenade left a white smoke trail behind it when thrown and would create sparks when it landed after being hurled, indicating that the grenades fuse could be a gas-release system. The grenade would be primed with pressing a button, release gas when in mid-air and then detonate when landing in a static position. This would make the grenade's detonation system depend on placement rather than timed detonation.
In Halo: Combat Evolved and Halo 2, four of these grenades may be carried at a time. This was reduced to two in Halo 3 due to the presence of four grenade types, but increased to three in Halo 3: ODST; in Halo: Reach the player is again able to carry only two grenades in normal gameplay, but may be given up to four in custom gamemodes.
This grenade can be effectively hurled and bounced around corners and travels farther than the Plasma Grenade; this can be used to quickly and aptly damage an attacker before he can move away from it, giving you an instant advantage in the close combat situation. It is also harder to see and has a shorter fuse, therefore making it harder to avoid and more useful for killing enemies on foot. In Halo: Combat Evolved, it also seems to have a larger blast radius than a Plasma Grenade. It has the largest casualty radius than the other grenade types in Halo 3. Also, since it is harder to see, having an enemy run over one by accident can happen more easily than with a bright blue plasma grenade.
The M9 HE-DP Grenade is best used when enemies gather together in tight groups. A well thrown grenade placed in the middle of a Covenant lance will kill most of the Grunts and damage an Elite's shields. With the shields damaged, players can easily kill the Sangheili. In addition, frag grenades should also be used against a group of Jackals, as their defense shields will not protect them from the blast. In Halo: Combat Evolved, the only Elites that can be killed with one detonation are Stealth Sangheili, with its downgraded shields. The M9 HE-DP Grenade is also commonly used against light-armored vehicles.
A multipurpose weapon, the fragmentation grenade can be used in corridors, to flush out occupants. The blast will severely damage player's energy shields allowing for easy follow up attacks. One frag grenade is considered as either aid in combat for quick damage before the fight starts, or as a tool to finish off an unshielded opponent. A grenade can be bounced off of a wall to ambush an enemy or kill your ambushers. Two frags is where this grenade becomes a killer all on its own. The first takes out the shields, the second finishes them off. If timed correctly, grenades can be planted in the path of an oncoming vehicle. Most drivers will not be able to react quickly enough, and will most likely be caught in the blast. Lighter vehicles will be easily flipped by concussive blast, and a heavily damaged vehicle will oftentimes simply be destroyed.
Another good multiplayer tactic is to throw one at the player's feet while back-pedaling when an enemy is charging at the player. When the grenade detonates, the other person should be in the blast radius of the grenade and have their shields damaged or be killed. This is useful to fight oncoming vehicles, preferably light-armored vehicles like Ghosts, Mongooses, or Warthogs. Frags are also very handy to kill opponents when used in conjunction with explosive objects. Destroying Fusion Coils or Plasma Batteries with a grenade means the grenade's damage plus the explosive's damage would hurt or kill the target more effectively than a single frag grenade.
The fragmentation grenade is also a good finishing tool since it is powerful enough to take down a spartan's shields, without the user being in line-of-sight of their target. Use an automatic weapon (Assault Rifle, Plasma Pistol/Rifle, SMG,) to take down their shields then throw the grenade at the person's feet once your mag is empty or overheated for the finishing blow.
The frag grenade can be used to 'nade jump'. Throwing a frag on the ground, standing over it, and jumping right before it explodes will send you skyward up to 25% higher than a regular jump. This is handy when trying to get to hard to reach places. For example, in Halo: Combat Evolved, on Blood Gulch you can grenade jump from the ground to the top of the base at blue or red.
List of appearances