Does the Scout's Ambush Master feature require a successful attack to activate it?

Question

The Scout subclass of the Rogue includes the 13th-level feature "Ambush Master" which says:

Starting at 13th level, you excel at leading ambushes and acting first in a fight.

You have advantage on initiative rolls. In addition, the first creature you hit during the first round of a combat becomes easier for you and others to strike; attack rolls against that target have advantage until the start of your next turn.

Because this says "the first creature you hit," does this mean you must make a successful attack roll in the first round of combat before any advantage will apply? Or does "hit" in this context apply to your very first attack roll because all that's needed is for the attempt to be made?

Answer 1

There is no “first creature you hit” until after you have hit something.

You have made the correct observation in your question when you write “you must make a successful attack roll in the first round of combat before any advantage will apply”. If you have not yet hit a creature this combat, there is no “first creature you hit”. You have to hit something for there to be a “first creature you hit”. So the Ambush Master feature does not give advantage on attack rolls until after you have successfully hit a target.