The VOIDRUNNER'S CODEX is coming! Explore new worlds, fight oppressive empires, fend off fearsome aliens, and wield deadly psionics with this comprehensive boxed set expansion for 5E and A5E!
I'd recommend against reducing a character's defense the more attacks that target them in a turn, as this will make focus fire an even more dominant tactic than it already is, and reduce the amount of interesting choice players have.