I’m in the middle of an epic duel with a fearsome foe. Unfortunately, he reduces me to 0 hit points and I fall unconscious right beside him. My wizard-friend tries to finish him off with a spell, but our opponent counterspells. Before my turn, my trusty bard-friend heals me with a healing word and I’m back in the fight. On my turn, I stand up and evaluate my chances. I decide to flee.
Do I know that my sworn enemy cannot take an attack of opportunity if I move away without disengaging, even though I was unconscious when he used his reaction for counterspell?
Or more generally: Do I know if someone already used their reaction?
Best Answer
It depends on your table
"Reactions" are a game concept, it's not something your character is aware of. So it depends entirely on what kind of seperation of in-character and meta-knowledge your game table uses.
There is no real right or wrong answer here, even if you do not allow meta knowledge, your character might still be able to realize this fact because their opponent is "occupied".
A round happens "at the same time", so they could dash out while they spot the wizard casting his counterspell. It seems likely that they wouldn't be able to focus on casting something and striking you down at the same time.
Alternatively, as mentioned by NautArch, your teammembers could shout when it's safe to go, if you decide to 'rule' that your character isn't completely aware of what was going on around him while he's downed.