Smoke from a variety of sources is common in combat.
Smoke can be placed on the battlefield from a number of sources:
- Smoke shells can be direct fired by most howitzers and guns 60mm or larger, using the Target Smoke command.
- Smoke shells can be indirect fired by most guns capable of it, via the artillery interface.
- Many infantry units carry smoke grenades which can be thrown a short distance.
- Many vehicles had smoke grenade launchers or smoke pots, which were used to quickly lay a smoke cloud in front of the vehicle to hide from an unexpected threat.
- Explosions (from HE shells or cookoffs) create clouds of smoke and/or dust.
- Burning vehicles cause a smoke pillar.
There are two main kinds of smoke shells represented in CMx2: a normal smoke round, and white phosphorus (WP) rounds. The normal smoke rounds hit the ground and burn, releasing smoke from a point source.
White phosphorus rounds contain a small bursting charge which scatters many small fragments of white phosphorus; white phosphorus spontaneously burns in the presents of oxygen. White phosphorus smoke is preferred for two reasons: the resulting smokescreen forms almost instantly, and the burning fragments themselves are dangerous to any infantry they hit. In CMBN, white phosphorus seems to generate smoke more quickly, and it lasts longer.
All units in the game which fire smoke rounds have normal rounds, or WP, but not both. Only a few American units fire WP smoke rounds:
- M4A3(75)W Early and Mid
- M8 HMC
- 81mm mortar (on-map or off)
- 4.2in mortars
All other smoke in the game is normal smoke (whether shells, mortars, grenades, or smoke pots).
The main effect of smoke is to obscure line of sight. With line of sight obscured, units cannot do targeted fire, nor is there any way to plot new area fire commands "into" the smoke. Thus, units behind smoke are nearly totally safe.
A player can plot area fire at action spots which will become obscured by smoke, and any such fires will continue even when the smoke has obscured the targeted action spots. Thus, if you want to give suppressive fire through a smoke screen you know is coming, get your fire support elements to start area fire before the smoke screen is laid. It is also possible to start suppressive fire after the smoke screen has been laid if you give the orders in advance. Keep your fire support units back with the pause command and give them a move command (and eventually a deploy) and, by selecting the end point of the command, a target (or target light) command to the action spot where you want suppressive fire. This order sequence must be given before the smoke screen is laid, but it will be executed after the smoke screen has obscured the target if properly timed with the pause command.
Other than sight obscuration, there is no effect of any kind of smoke on any units which move into it, or which it drifts over.
As of CMBN 1.00, both types of smoke shells had significant damaging effect, as if they were a high explosive shell which also causes smoke. See this post at the BF forums by Chad Harrison. (It is expected that WP smoke should cause casualties, but not normal smoke shells. So this may have been fixed in 1.01; this needs to be tested.)
Smoke grenades do not cause casualties or suppression.