Question as simple as title yet very hard to answer. I'm specifically referring to things like:
- Abrupt Jaunt variant wizard class feature,
- Wings of Cover spell,
or any other similar effect.
Can player use one of those in response to attack that he/she either can't perceive or doesn't know where will land? For example:
- Fireball (PC doesn't know where it hits until it hits, even if player does),
- Ranged attack (PC doesn't know whether he is being targeted or his teammate right next to him, even if player does),
- Sneak attack (PC doesn't know the attacker exist at all before being hit).