I'm working on house rules for advantage/disadvantage that makes the number of each matter, instead of any amount of each cancelling out. For this project I need to know how blindness and unseen targets generate disadvantage.
I don't know whether to consider the blindness condition and unseen attacking as two separate rules or one. Blindness gives (among other things) disadvantage to the creature's attacks against others.
My interpretation is that this is because they can't see attackers or targets.
An example situation is that a blinded Ranger shoots an arrow at another archer based on his last known position. He is blinded and the target is unseen. Is this two disadvantages or one?