Cover plays a huge role in Dawn of War 2
, moreso than it did in the first game as it's very common on most maps. This tip is designed simply to show the general types and how to recognize them.
The most common sort of cover is light cover. Light cover usually consists of tall grass, brush, small rocks, or relatively lightweight manmade defenses such as plank fences, barrels, and other similar items. Light cover is recognizable in the game by the yellow dots that show up when you hover your mouse over it. When you tell your unit to move, they'll position themselves as close as possible to how those dots are aligned, so make sure they're on the correct side of the cover.
Light cover provides a slight defense against enemy fire, decreases the amount of Suppression damage your units take, and increases their Suppression regeneration.
The next type is called heavy cover. Heavy cover, as the name would suggest, is usually found in concrete walls, heavy boulders, manmade bastions, metal bulkheads, or other similar places. Heavy cover shows up the same way light cover does, only with green dots instead of yellow ones.
Heavy cover offers the same bonuses against Suppression and enemy ranged damage that light cover does, only in greater amounts.
There are also many places throughout the game maps that feature a mixture of light and heavy cover in the same location. This "mixed" cover offers light or heavy protection on a model-by-model basis, as shown by the yellow or green movement dot. In the image below, the small rocks in the middle are only light cover, while the Shoota Boys who move to the flanks will be protected by the heavy cover of the larger boulders.
Another common sort of cover, though less common than the ones mentioned above, is building cover. Units garrisoned in buildings can still be damaged by fire, but to a much smaller effect than they would be in the open, and they also cannot be engaged in melee; it's often faster to destroy the building than it is to kill them. The biggest perk of building cover is that you can stack large amounts of units inside it, more than you could fit in an open space of the same size. This building, for example, is large enough to hold two Ork units and keep them protected.
The downside to this protection is that only a limited number can fire out of the windows, and there's no way to determine which shooter goes to which place. Planting a heavy gun team in a building might result in the heavy gunner pointing out a window that overlooks your own base, while his loaders fire their paltry small arms at the enemy. In this case, the building has a Shoota squad and Slugga squad loaded up at the same time, and despite having enough Shootas to cover all the windows, the top left window is being manned by a Slugga.
It's also worth noting that if the building is destroyed, any troops garrisoned inside it will be damaged considerably or outright killed as a result. Obviously. Also, building cover offers less protection from enemy fire than open heavy cover.