In Real Life
A smoke screen is smoke released to mask the movement or location of military units such as infantry, tanks, aircraft or ships. Smoke screens are commonly deployed either by a canister (such as a grenade) or generated by a vehicle (such as a tank or a warship). Whereas smoke screens would originally have been used to hide movement from enemies' line of sight, modern technology means that they are now also available in new forms; they can screen in the infrared as well as visible spectrum of light to prevent detection by infrared sensors or viewers, and also available for vehicles is a superdense form used to prevent laser beams of enemy target designators or range finders on vehicles.
Smoke screen is used either as a cover during an escape, or to deflect ATMs. In 18a these did not work, however, in 19a they are an indispensable upgrade for tanks with weak armor and/or health.Qnomei (talk) 00:29, May 7, 2014 (UTC)