Screen shake is easy, just include a worldcamerashake actor on it and a trigger for that animation. Most likely they will. For terrain disfiguration, most likely they'd make a decal that shows the impact area cracked or scorched a little that would stick around for awhile, but unlikely physical deformation. On an MMO, physical terrain deformation is not an easy thing to tackle. If they really wanted to, they might have a set of local offset limits so terrain can only deform up to a certain limit of like a foot or two, and have it slowly larp back to it's original form over a minute. Still, might be odd with some pathing or create a bunch of extra expenses to process and update that all, so I doubt they'd bother.