Examples of the Pestilent Double Bluff

The Pestilent Double Bluff is a level 15 convention.

Example 1

• It is the first turn of the game.
• Alice clues number 2 to Donald, touching a red 2 as a Play Clue.
• From Bob's perspective, this looks like a Finesse. Bob knows that he probably has the red 1 on his Finesse Position. Bob blind-plays his Finesse Position and it is yellow 1 and successfully plays. Bob now knows that he was Bluffed.
• Cathy sees that from Donald's perspective, a Finesse just occurred, and the 2 in Donald's hand is the yellow 2 (to connect to the yellow 1 that was blind-played). This is a problem (because the card really is red 2 and Donald will go on to misplay it).
• Cathy knows that Alice must be trying to communicate something extra. When this kind of thing happens, it is usually a Good Touch Bluff, which means that someone else already has the yellow 2 clued in their hand. However, this is not the case because Alice gave the clue on the first turn of the game and obviously no-one has any clued cards in their hand yet.
• This must be a Pestilent Double Bluff. Cathy can "heal" the situation by blind-playing his Finesse Position, and this was Alice's intent all along. Cathy blind-plays her Finesse Position and it is blue 1 and it successfully plays.
• From Donald's perspective, Alice's move looked like a Finesse after Bob blind-played the yellow 1. However, after Cathy also blind-played a card, Donald gasped in surprise. Something special must be going on, since a Finesse on the yellow 1 into the yellow 2 would never cause Cathy to blind-play.
• Subsequently, Donald knows that his 2 cannot be the yellow 2.
• Furthermore, Donald also knows that his 2 cannot be the blue 2, because then Bob would not have blind-played anything, but let Cathy fulfil the Finesse.
• Thus, Donald knows that this must be a Pestilent Double Bluff and marks his 2 as either a red 2, a green 2, or a purple 2.

Example 2

• Red 1 and blue 1 are played on the stacks.
• Alice clues number 3 to Donald, touching a blue 3 as a Play Clue.
• Bob knows that this is a Finesse, so he blind-plays his Finesse Position card (slot 1) as a blue 2. Instead, it is a red 2 and it successfully plays. Bob now knows that he was Bluffed instead.
• Cathy knows that something weird has just happened. Since red 2 connects to a number 3 clue, Donald will think that he has the red 3 (and it will go on to misplay).
• Cathy knows that this must be a Pestilent Double Bluff. She blind-plays her Finesse Position card (slot 1). It is purple 1 and it successfully plays.
• After the number 3 clue was given and the red 2 blind-played, Donald thought that his 3 was the red 3 (since 2 connects to 3). However, if it was red 3, then Cathy never would have blind-played. Thus, Donald knows that his 3 cannot be the red 3.
• Furthermore, since Bob did not wait for Cathy to play her purple 1, it is also not the purple 3.

Example 3

• Red 1, yellow 1 and purple 1 are played on the stacks.
• Alice clues number 3 to Donald, touching a green 3 as a Play Clue.
• Bob knows that this a 3 Bluff or a Finesse, so he blind-plays his Finesse Position card (slot 3). It is red 2 and it successfully plays. Bob now knows that he was Bluffed.
• Cathy knows that something weird has just happened. Since red 2 connects to a number 3 clue, Donald will think that he has the red 3 (and it will go on to misplay).
• However, in this case Cathy knows that Donald will not think he has the red 3, because Alice actually has both of them in her own hand.
• But Alice does not know that she has both of the red 3's in her hand — from Alice's perspective, Donald will go on to think that he has red 3.
• Cathy knows that Alice would never intentionally perform such a bad clue — she must be trying to communicate something extra.
• Cathy knows that this must be a Pestilent Double Bluff. She blind-plays her Finesse Position card (slot 1). It is purple 2 and it successfully plays.
• After the number 3 clue was given and the red 2 blind-played, Donald thought that his 3 was the red 3 (since 2 connects to 3). However, if it was red 3, then Cathy never would have blind-played. Thus, Donald knows that his 3 cannot be the red 3.
• Furthermore, since Bob did not wait for Cathy to play her purple 2, it is also not the purple 3.