Each player is dealt a certain number of hidden person cards. Consequently everyone knows some people who don't belong to the criminal ring. Each player must give these people an alibi if asked.
Everyone now has the task to find out through aimed guesses and clever deduction which person cards the other players have. Whoever knows that first, can expose the three criminals first.
2. The dealer deals
The dealer shuffles the 27 person cards (red backs); the player on his right
cuts the deck.
First, the dealer puts aside the three uppermost cards. These three cards
represent the three members of the criminal ring "Black Vienna".
Then he deals (face-down) the remaining 24 person cards, starting with the
player to his left. With three players each receives eight cards, with four
each receives six, and with six each receives four. If five players
participate, the dealer receives four cards, the other players five.
Each player now has secret information in her hand. Each player knows that
the persons represented on his cards are not the sought criminals. He must
give them an alibi, if asked.
Each player can make notes on his investigation sheet, marking the
cards that he possesses under his name with plus-signs (+), and under his
opponents with minus-signs (-). Everyone must hide their investigation sheet
during the game.
Each player can of course mark his sheet as he wishes to best assist him
in recording the results of investigations and to make deductions.
3. Investigations and answers
The dealer begins the investigation. He takes one of the three face up
investigation cards and places it in front of any other player. He thereby
asks this player to provide an alibi for any or all of the suspects shown on
the card.
The player who has been questioned then places one chip on the card for each
matching suspect card he holds in his hand; if he holds no listed suspects, he
places no chips. Thus if a player received the card "BLM" and he had "B"
in his hand but not "L" or "M", he must put exactly one chip on the
card.
The investigation card, on which now lie zero to three chips, remains down
before the interviewee, and he now asks the next question.
Thus, the game continues. The player asked a question always gets to ask
the next question.
4. Special investigations
Once each player has been questioned at least once and at least six
investigation cards have been played, special investigations may be
performed.
Whoever is asking a question may also take an investigation card in front of
another player but with no chips on it, and place both it and an investigation
card drawn normally in front of the player he's chosen. That player must
respond to each of these cards as instructed in #3 above. (Translator's
note: when trying to sort out the rules for the game, I interpreted this rule
differently - offering players a choice of a normal or special investigation.
Looking through the rules again, I think the above is the actual rule; I have
no idea whether the misinterpretation makes for a better game or not. But
anyone who directly or indirectly learned the game from Aaron Fuegi or I is
likely to have played by my misinterpretation.)
5. Deduction
Each player marks the results of the investigations into his investigation
sheet under the name of the interviewee and constantly supplements it through
clever deduction. Plus-signs are recommended (+) as well as minus-signs (-)
when certain a player has or doesn't have a certain card.
The goal of the deductions is to find what person cards other players have.
Because whoever first knows which person cards the other players have, knows
for a fact the three members of the criminal ring "Black Vienna".
(Translator's note: of course, it's not necessary to know which cards any
other player has to be certain of the makeup of the criminal ring...)
6. Accusations
Whoever believes they know the three members of the criminal ring knocks on the
table and says "Black Vienna".
Each player can do this at any time, whether or not they were involved in the
latest investigation.
At this point the game is interrupted. The player who has knocked makes an
accusation. He marks the initial letters of the three persons who in his
opinion belong to the criminal ring with three clear circles on his
investigation sheet. Then, he covers his investigation sheet, looks at the
three criminal ring cards, and checks whether his accusation is correct or
not.
If the accusation was not correct, then the game continues. The player who
made the wrong accusation still plays along, however he obviously may raise no
second accusation. His scored for this game is zero.
7. Game end
If the accusation is correct, however, the game is over. The successful
accuser has won the game and receives three points for each chip left in the
middle. Now the other players who have made no accusation may circle the
initial letters of the three people who they believe belong to the criminal
ring on their investigation sheets.
The three criminal cards are then uncovered visibly for everyone, and each
player who has the three criminal ring members correct receives one point for
each chip left in the middle. All other players receive zero points.
8. Unsuccessful investigation
If all players have accused incorrectly save one, the game is broken off. This
one player may ask one final question, and then must make an accusation. In
this case, this player receives one point per remaining chip if successful,
zero otherwise.
If three chips or fewer remain the game is also broken off. All players
receive zero points.
Second, here is a suggestion for how to handle players who have made incorrect guesses. I suggest that these players not be allowed to ask questions and should only answer them. The following is the fairest method I have come up with for handling this. Wait until the first time a question is asked of a player who has previously made an incorrect guess. After that question is answered, choose a random player among the others to ask the next question (call this a free question). The next time this situation comes up, the next player (skipping players who have made previous incorrect guesses) clockwise around the table from the last person to ask a free question gets to ask this free question.