Uses a special type of artillery to create smoke in order to cover your movements. The enemy has this also. Costs 1 TP and requires a signaler. It blocks LoS just like a tree does. It can get rid of the trees on your battlefield.
Smoke screens have been used to cover movements of infantry, vehicles or ships, and were a common sight in naval engagements during WW1 and WW2. They have been extensively used during October 1943 when the Red Army crossed River Dnieper where a 30 kilometres (19 miles) long smoke screen was used and at the Battle of Anzio when US Chemical Corps maintained 25 kilometres (16 miles) long smoke screen for 2 months providing the beachhead complete protection against the Axis trying to observe the area. In modern warfare they are used to disturb enemy infrared scanners, range finders and laser beam target designators.