A smoke grenade is a hand grenade specifically designed to release smoke when detonated rather than an explosion.
Grenades can emit plain gray/white smoke to screen positions from observation or targeting. Various colors can also be used as a signalling aid, visible from a fair distance away (especially from the air).
In Battlefield Vietnam, the US and ARVNScout classes come equipped with yellow smoke grenades. It is deployed like a grenade, but is non-lethal and creates a relatively large plume of smoke where it lands. It is of no use in Singleplayer or Co-op , as it is completely ignored by AI soldiers. In Multiplayer, it can offer a limited screening effect or can be used as a distraction. If a team is well coordinated, it can serve as a marker for air support.
Each Scout equipped with smoke grenades is issued a total of 3.
Because Battlefield Vietnam features different loadouts for each faction, this list may not be specific enough. Please see each faction's respective page for information on individual weapon kits and loadouts.
The Smoke Grenade is included in the Assault kit in the game Battlefield 2. Instead of having a spherical shape like the frag grenade, it has a cylindrical shape (sort of looks like a tiny can). It is thrown like a frag grenade (default Left-Mouse-Button for normal throw, default Right-Mouse-Button for a controlled distance throw), but instead releases smoke. The smoke grenade has many uses.
Orders issued by squad leaders or the Commander also place a smoke effect that can only be seen by the squad.
The Assault kit in Battlefield 2142 has access to the SG-34 Smoke Grenade, which is used mainly as a visual obscurant. Its effect is rather weak and short-lived, and does not protect from AI-controlled sentry guns (or bots in singleplayer).
While not a usable weapon, the smoke grenade appears as signals for the squad to regroup on to advance the story. It emits red smoke from it and is not thrown but any particular character. It can appear right close to the player as in many missions or appear very far from the player such as in missions like Acta Non Verba and Crossing Over right to the point where a vehicle is needed to get there.
The smoke grenade returns in Battlefield Play4Free. Unlike its iteration in Battlefield 2, the smoke grenades can only be equipped after training is acquired for it, much like fragmentation grenades. It is a tier 2 training unlock. When tossed, it will produce a large cloud of smoke after about four second. The cloud makes it impossible for anybody to spot any person within the smoke. One may have a maximum of 5 smoke grenades at any one point, and it may be assigned to a specific numerical key.
The M18 Smoke Grenade was announced as an available weapon in Battlefield 3 on the GamesCom Fact Sheet, but is not used by the player as of the game's release. It is only seen in non-player-controlled situations, such as the seaborne assault on Kharg Island in multiplayer. On the Co-Op mission The Eleventh Hour, smoke grenades are thrown by French Police to cover the GIGN soldiers who advance into the Stock Exchange (and are subsequently gunned down).