In Starcraft 1 I vaguely remember that burrowed units wouldn't take splash damage (but would take damage from Psi-Storm), and units under dark swam did take splash damage, but you could avoid this by being burrowed.
In StarCraft 2 I haven't seen any information on if there are any differences between a burrowed and un-burrowed unit other than the visibility. Do burrowed units in SC2 take splash damage as normal? Does this depend on if they are detected or not? How about Glaive-worm bounces off a non-burrowed unit?
Cheers!
Best Answer
Glaive-worms will only bounce to visible targets. If you don't have some way to detect the burrowed enemy, your mutalisks won't randomly hit them.
Burrowed Units take splash damage, the same as if they weren't burrowed.