- “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/Antimatériel Incendiary grenade is a multi-purposed infantry explosives munition first produced by the Sacred Promissory just a few months before the Great Schism. The T-3 AP/AM can be thrown 10 metres (33 ft) by the average soldier, but is mainly used by Brute Stalkers. Upon impact with a hard surface, the casing converts to liquid form, burning at around 2200 °C (3992 °F), and causing significant damage to vehicles and infantry alike, with a killing radius of 3.4 metres (11 ft) and a casualty radius of 4.7 metres (15 ft). 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. However, the fact that the T-3 uses a highly toxic Caesium mixture makes any human flesh which comes in contact with it inedible for Brute consumption.
Killing someone in multiplayer with this grenade will award the player with the Incineration Medal.
In campaign, it is a very effective weapon against the Flood. It can kill up to three Flood Combat Forms or Flood Pure Forms in a close group. They are also useful against large swarms of Infection Forms. When stuck to a Flood Carrier Form, the resulting fire will burn thoroughly and not release any Infection Forms from the Carrier.
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."
- It was mistakenly dubbed as a UNSC weapon in the Inside Halo Machinima.
- Its function is very similar to a Molotov Cocktail. For this reason, players sometimes refer to the Incendiary grenade with names such as, "Anti-Water Balloon", "Satan's grenade", "Lava Can", and/or "The Cocktail".
- Even though Incendiary grenade is the proper name, it is referred to as the Firebomb grenade in the game.
- It only appears in four Halo 3 campaign levels, The Ark, The Covenant, Cortana and Halo.
- It does not appear by default on any Multiplayer map, nor does it regenerate using the "grenade regeneration" option. They are only available if they have been previously added in Forge.
- Only Brute Stalkers use incendiary grenades in the Halo 3 campaign, and dead Brute Stalkers are your only source of these grenades.
- The Incendiary grenade will kill any Chieftain in a single throw on almost any difficulty, except Legendary, as long the Chieftain gets the bulk of the explosion, spreading the fire all along the body, not just the limbs. It is a guaranteed kill unless the Chieftain activates an Invincibility power-up.
- It can be used to create a "wall of fire", burning those who chose to cross it, restricting enemy movement in the area. It is a tactic very useful in skirmish games such as Assault or CTF.
- If thrown into a Warthog passenger seat at the proper angle, it will get stuck, like the Frag grenade, and bounce.
- Incendiarys generate a small explosion if shot while active and in any occasion in Halo 3 and Halo 3: ODST Campaign, instead of a pool of fire. They must be ignited prior to impacting a surface to create the pool of fire.
- The Incendiarys do not shower an area with fire if destroyed in midair for this reason.
- If a Flood Carrier Form is hit by an Incendiary, it will not release any Infection forms.
- If you hijack a tank and plant a fire bomb grenade, you will receive damage as well.
- It is the only item in the Brute Sandbox that is not labelled with a number containing 5 or 2, and the only other item in that classification other than the Spike grenade and the Gravity Hammer that has a single-digit number in its designation.
- Data Hive has the most Incendiarys in Halo 3: ODST.
- If a player is set on fire during a Forge match, but attempts to 'extinguish' the fire by turning into Oracle mode, when the player returns to player mode they will still be on fire. This is because the fire has been 'preserved', possibly to even out gameplay during forge.