M9 fragmentation grenade

The UNSC-issued standard fragmentation grenade functions in a manner very similar to contemporary hand grenades. A blast bursts the grenade's shell open and sends thousands of small metal pieces flying at extreme speed, causing damage to energy shields and flesh in around ten meters (30ft) radius. Four may be carried at a time. An "infinite grenades" option is available in multiplayer on a single Xbox, as well as in all multiplayer Halo PC games.

Advantages
This grenade can be bounced around corners and travels farther than the Plasma grenade. 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. It also seems to have a larger blast radius than a plasma grenade in Halo 1.

Disadvantages
Unlike the Plasma grenade, this grenade doesn't stick to objects, making it harder to hit vehicles. Since it is harder to see, running over one by accident can happen more easily than with a luminescent plasma grenade.

Legendary Tactics
Use the M9 HE-DP Grenade when elites and grunts are in large or small groups as this will kill many grunts, damage elite's shields and sometimes grunts will walk around with their hands over their heads for a short period of time making them quick work with the battle rifle. (Note: This tactic works extremely well on Cairo Station when enemies come out of boarding ships.)

Multiplayer Tactics


A multipurpose weapon, the fragmentation grenade can be used in corridors to flush out occupants. If lobbed under a vehicle, the explosion will either kill or severely injure the occupants. 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.

Effective Against
Anything land based except for heavy tanks such as the Scorpion Tank and the Wraith Tank.