Hypersmurf
Moderatarrrrh...
From the Sage Advice chat transcript on the main page:
Q: Do creatures who use invisibility to flank an opponent with an ally grant a flanking bonus to their (uninvisible) ally? It is important for a combatant who has cast invisibility on oneself to remain invisible by not attacking. If awareness is a prerequisite for flanking, what about an invisible creature who purposely brings attention to himself by making loud noises?
A: No, they don't. If a creature is unseen so that an opponent loses his/her Dex bonus against that creature, then the creature can’t give any of its allies a flanking bonus. The creature can get a flanking bonus from an ally the creature can see, however.
Gah! What?!
-Hyp.
Q: Do creatures who use invisibility to flank an opponent with an ally grant a flanking bonus to their (uninvisible) ally? It is important for a combatant who has cast invisibility on oneself to remain invisible by not attacking. If awareness is a prerequisite for flanking, what about an invisible creature who purposely brings attention to himself by making loud noises?
A: No, they don't. If a creature is unseen so that an opponent loses his/her Dex bonus against that creature, then the creature can’t give any of its allies a flanking bonus. The creature can get a flanking bonus from an ally the creature can see, however.
Gah! What?!
-Hyp.