Level 15 - Double Bluffs

Special Moves

The Double Bluff

• Sometimes, Bob and Cathy will have playable cards on their Finesse Position. In this situation, you might be able to perform a Double Finesse to get them to immediately blind-play. However, this is only possible if both cards are related, and the "connecting" card is available to Play Clue.
• In the same way that you can sometimes perform a Bluff when a Finesse is not available, you can also sometimes perform a Double Bluff when a Double Finesse is not available. This is performed by giving a Play Clue to a non-trash card that is not a legal Bluff-target.
• For example, in a 4-player game:
  • Red 1 is currently played on the stacks.
  • Alice clues Donald red, which touches a red 4 as a Play Clue.
  • Since red 4 must be playable right now, Bob thinks he has the red 2 and the red 3. Bob blind-plays his Finesse Position card, but it is actually a blue 1.
  • Cathy sees that Bob blind-played because of the red clue. However, the red 4 is a non-trash card and not a legal Bluff-target. Thus, Alice must intend for a Double Bluff instead of a single Bluff. Cathy blind-plays her Finesse Position card and it is a yellow 1.
  • At first, Donald thought that the red card in his hand was red 2 (as a Play Clue).
  • After Bob blind-played, Donald thought that the red card in his hand was red 3 (as a Bluff).
  • After Cathy blind-played, Donald knows that his card was not a valid Bluff target for the blue 1, and so he must have the red 4 (as a Double Bluff).
    • For players not yet at level 16, Donald would also mark the card as a potential red 5 in addition to a red 4.

• Similar to other kinds of Bluffs, Double Bluffs may only be performed from Bluff Seat, and must be demonstrated immediately. In other words, both blind-plays must occur on the two turns directly following the clue.
• Double Bluffs are valid even if the card which Bob blind-plays connects to the card which is clued by Alice.
  • For example, the previous scenario works equally well if Bob's blue 1 is replaced by a red 2.
  • In this situation, Cathy would not know whether the clue is a Double Bluff or Double Finesse until after she blind-plays.
  • This used to be called a Double Half Bluff, but this term was phased out because the distinction is not really relevant: Cathy does not care which situation she is in, as she is required to blind-play immediately either way.
• Some more-specific types of Double Bluffs are listed below.

The Triple Bluff (Illegal)

• We agree that all Bluff-style clues should resolve after two-blind plays.
• Thus, there is no such thing as a Triple Bluff.

The Hard Double Bluff

• Similar to a Hard 3 Bluff, it is also possible to perform a Hard Double Bluff.
• For example, in a 4-player game:
  • No cards are played on the stacks.
  • Alice clues number 4 to Donald, touching a red 4 as a Play Clue.
  • Bob blind-plays red 1 from his Finesse Position.
  • Cathy blind-plays red 2 from her Finesse Position.
  • Even though red 1 and red 2 are the same suit as the red 4, the team knows that no-one is promised the red 3, since two blind-plays happened immediately after the clue.
  • Donald knows that his clued card can be any 4.

The Pestilent Double Bluff (PDB)

• Normally, a Double Bluff can only be initiated with a card that is not a legal Bluff-target. However, this is not always true.
• Sometimes, Alice can clue a legal Bluff-target to make Bob blind-play, and then "force" Cathy to blind-play as well in order to resynchronize the information about the identity of the clued card.
• This is called a Pestilent Double Bluff to distinguish it from the more-normal Double Bluff where a non-legal Bluff-target is used.
• For example, in a 4-player game:
  • It is the first turn of the game and nothing is played on the stacks.
  • Alice clues number 2 to Donald, touching a red 2 as a Play Clue.
  • Bob blind-plays a blue 1 from his Finesse Position.
  • Cathy sees that right now, Donald will assume that he has the blue 2 (because it directly connects to the blue 1 that Bob blind-played). This is bad, because the card is really a red 2.
  • Cathy knows that because information is still not synchronized amongst the team, Alice must intend for Cathy to blind-play a card as a Pestilent Double Bluff.
  • Cathy blind-plays her Finesse Position. It is a green 1 and it successfully plays.
  • At first, Donald thought that his 2 was either a blue 2 (as a Finesse on Bob) or a green 2 (as a Finesse on Cathy).
  • After Bob blind-played, Donald thought that his 2 was a blue 2 (as a Finesse on Bob).
  • After Cathy blind-played, Donald knows that something weird happened. If his 2 really was blue 2, then Cathy would not have blind-played anything, so his 2 cannot be blue 2.
  • Donald knows that his 2 cannot be green 2 either, or else Bob would not have blind-played anything. (He would have waited for Cathy to blind-play.)
  • Thus, Donald marks his 2 as either red 2, yellow 2, or purple 2.

• More examples of a Pestilent Double Bluff can be found here.

General Principles

Deferring a Bluff

• From Urgency Principle, we know that players are allowed to defer a Finesse or a Bluff in order to do a Finesse or Bluff of their own. And indeed, when players see a really good clue, they should probably defer blind-playing to give the clue. But there are limits.
• When a player knows for sure that they are Finessed (instead of Bluffed), then deferring a Finesse (to perform another Finesse or Bluff) is great! It has almost no downsides, other than the obvious loss of Tempo. Everyone on the team is "in the know", so to speak.
• When a player could be Bluffed, deferring a Bluff can be extremely dangerous because it causes Information Desynchronization throughout the team.
• Deferring a Bluff to perform a Finesse can be pretty clear, depending on the situation. It should be done sparingly.
  • Note that deferring a Bluff to perform a Finesse can potentially lose the game if the original cluer is performing a Double Half Bluff. So there is some risk involved.
• Deferring a Bluff to perform another Bluff is much worse. Since the Bluff was not immediately resolved, the game state "fractures" into two valid game states for the receivers of each clue (e.g. the player who received the clue that initiated the first Bluff, and the player who received the clue that initiated the Deferred Bluff). This means that these two players will have to entertain two entire hypothetical game states in their mind and build upon each hypothetical with each new piece of information. This makes it extremely difficult for them to plan ahead or make correct decisions during their turns.
• Thus, deferring a Bluff to do another Bluff should almost never be performed.
• Also, see the below section on Deferring a Double Bluff.

Deferring a Double Bluff

• First, see the section on Deferring a Bluff.
• If Bob suspects that Alice is performing a Double Bluff, then Bob should never defer. It is very important that Double Bluffs resolve immediately.
• Similarly, if Bob blind-plays, and Cathy can not rule out a Double Bluff, then Cathy should never defer. (If Cathy defers, it will cause an unrecoverable Information Desynchronization, because her future blind-play will not be interpreted as related to the Double Bluff.)

A Table for Deferring Bluffs

Alice is deferring a	to perform a	Ok?
Finesse	Finesse	Yes!
Finesse	Bluff	Yes!
Bluff	Finesse	Sometimes, use sparingly
Bluff	Bluff	Almost never do this
Double Bluff (first blind-player)	Finesse	No, never do this
Double Bluff (first blind-player)	Bluff	No, never do this
Double Bluff (second blind-player)	Finesse	No, never do this
Double Bluff (second blind-player)	Bluff	No, never do this

Interaction between Bob's Truth Principle and Occam's Razor

• First, see the sections on Bob's Truth Principle and Occam's Razor.
• Normally, Bob follows Occam's Razor - he assumes that clues mean the thing with the least amount of blind-plays and Prompts.
• However, sometimes Bob can see that a clue is either a Double Bluff or a Finesse, where the Finesse needs more blind-plays than the Bluff.
• In this situation, even though the Finesse requires more blind-plays, we agree that Bob should always assume the Finesse interpretation because of Bob's Truth Principle.
• For example in a 3-player game:
  • On the first turn of the game, Alice clues number 4, touching Bob's slot 1 card as a Play Clue.
  • Bob sees Cathy's Finesse Position card is a playable red 1.
  • Thus, Bob knows that Alice's clue can either be:
    • a Reverse Finesse on a red 4, meaning that Cathy will blind-play the red 1, and then Bob will blind-play the red 2 and the red 3
    • a Double Bluff, meaning that Bob will blind-play some playable card and then Cathy will blind-play the red 1
  • Bob knows that in this situation, Bob's Truth Principle applies, so he knows it must be a Reverse Finesse instead of a Double Bluff.