Incendiary Grenades are devices that burn at extremely high temperatures through a violent chemical reaction. They may be filled with materials such as thermite, white phosphorus, or thickened fuel. Practical uses of grenades of this type include the destruction of munition caches, artillery pieces, and vehicles to prevent their use by enemy forces.
Four different incendiary grenades appear in the Battlefield series: the American M34 in Battlefield 4, the M14 Incendiary and Molotov cocktail in Battlefield Hardline, and the British No. 27 in Battlefield 1.
— Battlelog description)
The M34 Incendiary grenade is a new weapon featured in Battlefield 4. A short time after thrown, it emits a great deal of heat that can damage any enemy infantry within its radius, and also through walls if enemy infantry is standing close on the opposite side of where the grenade is. The fire and resulting smoke that the grenade emits can easily be used for area denial as well as for visual obstruction.
Damage inflicted by the M34 will continue for a short while after leaving the grenade's radius. Players with good health may survive with 1% health from a single M34; players with low health may be killed by the initial "hits" from the grenade. Care should also be taken after the grenade has seemingly expired as the resulting smoke is also capable of damaging players shortly afterwards.
The M34 cannot damage deployed explosives, but may damage other gadgets. It is, as its name would suggest, capable of setting the dry grass ablaze found in various Second Assault maps. Players can also unlock the Gunner Incendiary weapon for IFV and MBT gunner stations.
The M34 was rebalanced along with the other grenades in Battlefield 4 with the Fall 2014 patch, although the M34 only had its resupply time increased from 8 seconds to 25 seconds, taking the same amount of time to resupply as the M67 Grenade and RGO Impact. The grenade rebalancing was intended to reduce grenade spam and make grenades more of a tactical tool.
Two incendiary grenades appear in Battlefield Hardline: The Incendiary Device and the Molotov. The two only differ in appearance, and buying one will also unlock the other.
Unlike in Battlefield 4, the fire now spreads on the ground and catches objects on fire, rather than simply making a short-lasting cloud of fire. Incendiary grenades and Molotovs thrown by teammates will appear as blue flames, enabling the player to differentiate.
The Incendiary Device is a grenade featured in Battlefield Hardline. It is used by the Law Enforcement.
The Molotov is a grenade featured in Battlefield Hardline. It was first seen in the Battlefield Hardline: Rescue Multiplayer Gameplay Trailer, being used by the Criminals.
— In-game description
The Incendiary Grenade is one of several grenade types available to players in Battlefield 1. It inflicts continuous damage to enemies caught within the grenade radius and additional burn damage afterward. Afterburn damage can be reduced by going prone away from the fire, which also shortens burn duration. Damage is increased while sprinting. Incendiary grenades can also damage all vehicles to some extent, and injure exposed occupants.
- The M14 is referred to as "incendiarydev cop" within the Beta game files.
- The June Beta had the Molotov present in the game files, however it used the same model and statistical files as Battlefield 4's M34 grenade.
- The Molotov was actually first seen in the Official Teaser Trailer, depicted in live-action footage.