According to the rulebook, when using Masquerade, the cards passed between players must remain invisible until each player chooses the card to pass and places it down. I've always assumed it means that the passing itself is also done when the cards are face-down, which makes it the only card in the game that adds uncertainty to the number of VPs each player has. It was strange, but interesting to play nonetheless.
Lately, however, I've begun playing "Androminion", and noticed that when passing cards using Masquerade in this version, the cards are passed face-up. I've checked the rulebook again, and it DOES seem like this is a gray area: the cards to pass should be selected when all the cards are face-down, but what happens later is not specified.
So - which is the 'correct' use of Masquerade? Passing cards face-up, so all the players can fully see the implications of this turn, or passing them face-down, adding a bit of uncertainty to the game?