- Monk is marked by Fighter.
- Monk attacks Fighter.
- Monk uses Flurry of Blows on a different creature.
Does the Fighter get to use Combat Challenge to attack the Monk?
UPDATE: I found this thread that argues that FoB is an attack. Whether or not that argument is correct, this suggests at least three possible paths of reasoning for this question that I'd like to explore; in particular, the third one:
- Flurry of Blows is an attack and triggers mark retaliation. (argument: it has a target and deals damage, like post-errata magic missile)
- Flurry of Blows is not an attack and does not trigger mark retaliation. (argument: it doesn't have an attack roll)
- Flurry of Blows is part of the same attack and does not trigger mark retaliation. (argument: it is like hunter's quarry, warlock's curse, or rogue's sneak attack)