are you able to add deft strike to your attack of opportunity if you have already used it on your normal turn?

I would say no because the feature says you can use it once on each of your turns. Not once per turn.

thanks kreen. I wasn't sure.

My buddy says you can use it once each of your turns as in once for regular turn and once for reaction.

Quote from jv44z4b8te >>

My buddy says you can use it once each of your turns as in once for regular turn and once for reaction.

 That's true for stuff like sneak attack that says it can be used 'once per turn,' it isn't true for deft strike because it says 'once on each of your turns.'

Yep. The “your” is the sticking point. If that wasn’t there then you could use it on a reaction on another turn. But it is, so you can’t.