Situation: I run the Brotherhood agenda, I have a Brotherhood character and another character with Head of a Dwarf. I win dominance (or an unopposed challenge). Which character gets the power?
Infamy and the Brotherhood Agenda do not conflict because of the "may" vs. "must" nature of the two effects.
But the real question with Head of a Dwarf is what to do about the "you must put the power on a character with the attachment" effect, not the Infamy. That effect does conflict with the Agenda, but that conflict doesn't prevent the power from actually being claimed in the first place. So since the effects conflict, the First Player (not the active player) decides which one controls - and thus where the power goes.
Arthur Ganeshister said:
Infamy always goes first
Not quite, because the character MUST claim power regardless of his having Infamy. The player can choose to claim power on the character through infamy, but equally he can choose not to. However, when he tries to claim it for his house instead, the replacement effect of Head of a Dwarf kicks in and then the power must be moved to that character. However, the Brotherhood agenda institutes a replacement effect too, and unless Head of a Dwarf is on a Brotherhood character the replacement effects will conflict. In almost circumstances when two game-effects conflict, the first player decides on how they resolve, so I suspect in this case the first player would decide if it goes on the Head of a Dwarf character or the Brotherhood character.
Edit:
Godamn it ktom, why are you so fast?