Hiding behind an illusion is not the same thing as having cover. A real wall provides cover. An illusory wall does not, though it can block line of sight (which is not the same as granting cover). #wotcstaff https://t.co/AAqRbdRwXx

— Christopher Perkins (@ChrisPerkinsDnD) January 6, 2019

If a creature is heavily obscured and has cover, it gains the benefits of the cover and the benefits of being invisible, which is why cover doesn’t use the advantage/disadvantage mechanic but invisibility does. #wotcstaff

— Christopher Perkins (@ChrisPerkinsDnD) January 6, 2019

would this be a blanket factor for all things with perception check/ passive perception? Or does this specifically make a difference because some creatures see through illusions (like dragons i believe innately?) Only specifying because ‘illusion’ and fog obvious are not a wall** ** but would then fog be considered a cover or no then in this example because its not physical?

— Robin Tipton (@Cinderluna) January 6, 2019

Fog won’t stop an arrow, so it’s not cover, but it can lightly or heavily obscure you, making you harder if not impossible to see. #wotcstaff https://t.co/gnYcxO3wyl

— Christopher Perkins (@ChrisPerkinsDnD) January 6, 2019