The Horizon Walker ranger archetype from Xanathar's Guide to Everything gains the Spectral Defense class feature at 15th level (p. 43):
At 15th level, your ability to move between planes enables you to slip
through the planar boundaries to lessen the harm done to you during
battle. When you take damage from an attack, you can use your reaction
to give yourself resistance to all of that attack's damage on this
turn.
Say an enemy attacks a Horizon Walker ranger with a flame tongue longsword and uses Divine Smite, giving the attack 3 different damage types.
If the ranger uses their reaction to use Spectral Defense, does that mean that for the rest of that turn, they have resistance to all 3 types of damage? If the enemy tries to do the same thing again, does the ranger still have resistance, since it says for the turn?
Best Answer
The resistance does not last for the rest of your turn
The Spectral Defense feature states:
Compare this to something like the shield which states:
It explicitly states that you have the AC boost until the start of your next turn, which the Spectral Defense feature does not.
That said, the Spectral Defense feature does have incredibly unusual wording as it includes "on this turn". The only time I can see this having an effect if the same attack that damaged you later does more damage on that same turn. It also prevents future damage from the same attack that occurs on later turns from being resisted. I don't know when these niche scenarios would occur.