Type-3 Antipersonnel/Antimatériel Incendiary grenade

"It sure don't seem like it was meant for burnin' material, seems more like it was meant for burnin' personnel."

- Anonymous E2-BAG/1/7 serviceman

The Type-3 Antipersonnel/Antimateriel Incendiary Grenade, colloquially known as the "Firebomb" or the "Flame Grenade", is a Brute grenade.

It is a multi-purposed infantry explosives munition and can be thrown 10 meters (32.8 feet) by the average soldier. Upon impact with a hard surface, the casing converts to liquid form, burning at 2200 °C (3992 °F) and causing significant damage to vehicles and infantry alike, automatically killing all nearby infantry in a 3.4 meter (8 foot) radius. The gel-like filler substance also escapes from the burning casing, splashing over nearby objects and causing significant damage as it burns for 4.5 seconds. Killing someone in multiplayer with this grenade will award the player with the Incineration Medal.

Quotes
The following are observations of the Type-3 Incendiary Grenade from servicemen of the UNSC Marine Corps unit E2-BAG/1/7.

"The filler seems to be a liquid or a gel or something; it dissipates pretty rapidly under water—I don't know how it would behave in hard vacuum."

"It doesn't burn under water, unless it's already on something and burning. A "thermite", otherwise heat, grenade will burn under water and that crap has been around forever. Hey, is it just me or does Brute tech seem to be all over the map? Either there's no info sharing on Brutonia or something bad happened."

"Baby Kongs use 'em exclusively as AP grenades. Kongs tend to capture or abandon material more often than they deny it."

"None of the other alien foxtrots use 'em. Either the bravo kilos don't trust 'em with 'em or the rest of 'em ain't as keen on burnin' folk as kilos are."

Trivia

 * One Incendiary Grenade, can kill up to three Combat Flood Forms or Pure Forms (if they are close-knit in a large group). The grenade is also useful against large swarms of Flood Infection Forms. When stuck to a Flood Carrier Form, the resulting fire will not release or disperse any Flood Infection Forms from the Carrier as it burns all of its innards.
 * The Incendiary Grenade, will kill any Chieftain in a single throw on any difficulty, as long as the player hits the Chieftain and gets the bulk of the explosion (spreading all along the body, not just the legs or such). It is almost always a guaranteed kill unless one of the Chieftain activates an Invincibility power-up.
 * The Firebomb can kill any player with one throw in custom games, burning them as they move.
 * It can also be used to create a "wall of fire" that restricts enemy movement in the area. This makes it very useful in skirmish games such as Assault and CTF.
 * It, like all other grenades, can be shot and detonated by a weapon.
 * It was created by the Brutes after the Covenant Civil War in hopes of retaking High Charity. The Covenant was developing the technology after the events of Halo: Combat Evolved.
 * The Firebomb, is one of two Brute-manufactured grenades in Halo 3.
 * It does not appear by default on any map. If you turn on the "grenade regeneration" option, all grenades will regenerate, except the Firebomb grenade.
 * This is sometimes referred to as a "cheap, instant flamethrower" by players.
 * It can be used in a Warthog Jump.
 * Even though Incendiary Grenade is the proper name, it is referred to as the Firebomb Grenade in the game (most likely because it is listed in Forge as Firebomb Grenade).
 * The likely reason for not appearing in multiplayer is because of frame rate or balance issues.
 * There is a glitch where no fire appears, but your opponent still dies.
 * The only time it appears in the Halo 3 campaign in The Ark, The Covenant, Cortana and Halo.
 * Only Brute Stalkers use incendiary grenades in The Halo 3 campaign. Killing Brute Stalkers is also your main reserve of these type of grenade.
 * The grenade is not found by default on any multiplayer map, nor is it acquired using the "Grenade regeneration" option. The only way a player can obtain one on a multiplayer map is if they map has been edited in forge, and Firebomb grenades were added.