Cover (Long War)

In Long War, cover works much the same as it usually does, but cover also gives you Damage reduction. Low cover gives 30 Defense (changed from vanilla), as well as .66 damage reduction (i.e. 2/3 chance to reduce damage by 1 and 1/3 chance to reduce damage by 0). Hard or High cover gives 45 Defense (also changed from vanilla) as well as 1 damage reduction. Hunkering down doubles Defense and damage reduction.

Cover is generally a little tougher to destroy than it is in vanilla. Explosives do less damage the further an object is from the center of the explosion, so you'll find explosives no longer reliably blow up everything highlighted in red like they tend to do in vanilla. Cover near the center of the explosion usually is destroyed however. Engineers with the Sapper perk have a bonus to destroying cover, meaning their grenades will blow up more of the cover in the area of effect than other soldiers'.

High cover also has the advantage of breaking line of sight, provided that the soldier isn't standing on a corner and peeking out.