I Know You Know I Know: Difference between revisions

'''Lando:''' Thrawn or no Thrawn, the Empire ''is'' still [[Vestigial Empire|down to eight sectors]]. Maybe this is really all he's going for, hoping to confuse Coruscant so badly it just freezes up.<br />

'''Han:''' Who knows? That's what drives you so crazy about him. You try to do something and odds are it's exactly what he wanted you to do. You stand still and don't do anything, and he runs a smartrope around you. }}

** Zhuge Liang is the '''master''' of this trope. Various plans include:

*** Empty City: Zhuge Liang sits alone in an empty city playing his harp while a rival army comes up. They know that Zhuge is a genius and is obviously up to something. Knowing they would know this, the city ''really is empty'', and the whole thing was a stall tactic. That worked.

{{quote| '''Silk:''' Does he know that you know?<br />

'''Ambassador:''' Yes, but I don't think that he's aware that I know that he knows that I know. }}

** A Fourth Doctor book has the Doctor going on and on like this, until Sarah Jane Smith tells him to shut up.

{{quote| '''Sarah:''' You know they're lying.<br />

* Similar to the above example (but fewer levels), Richie in ''[[The Class (TV)|The Class]]'' must determine how Duncan's date went for Nicole, but since he's a [[Bad Liar]], he ends up revealing Nicole's secret, then Duncan's secret, then both.

* During Draft Day betting at ''[[Sports Night]]'' Dana and Casey try to figure out if the other knows anything about Tommy Castro's knees, and if so, do they know that the other person actually doesn't know anything about... etc. Ends when Casey explains the entire [[I Know You Know I Know]] situation to Dan, while wired so Dana can hear him.

** Also in the regular series episode "Let's Kill Hitler", between the Doctor and River. {{spoiler|Though it doesn't matter, because she's already poisoned him.}}

* Happens quite a few times in ''[[Yes Minister]]''. Especially funny due to Sir Humphrey's penchant for [[Sesquipedalian Loquaciousness]].

 

== Sport ==

* In baseball, when one team manages to figure out the second team's signals they'll usually try to only act on that knowledge at a critical point in the game. The second manager might intentionally allow them to try and steal the signal so at the critical point they think they know what's being planned. Which could cause paranoia in the first manager if the signal seemed too easy to steal, leading to suspicion of a setup. Which the second manager would know, so...

** In another baseball example, catcher Carlton Fisk once managed to confuse a batter by talking about how he knew the batter knew the pitcher was ignoring Fisk and only throwing fastballs down the middle, and the pitcher knew Fisk knew the batter knew but wouldn't listen to when Fisk said he was signalling for curveballs (he was actually signalling for fastballs...down the middle). After an epic performance which included Fisk screaming at the pitcher to throw the curveball and going out to the mound, yelling and waving his arms around, the batter was so screwed up trying to figure out who knew what was supposed to happen he could only watch a third strike fastball go right down middle.

{{quote| '''Vaarsuvius:''' ...which in turn means that he knew that you would know that {{spoiler|he was in the empire}}, and that you would know that he would know that you knew.<br />

'''Elan:''' Which means... that I'm totally confused. }}

{{quote| '''Doc Scratch:''' Naturally, the Thief [Vriska] knew this was her intent all along. ... <br />

And the Seer [Terezi] knew the Thief knew all this as well. <br />

* Used without being named in one of Ayla's ''[[Whateley Universe]]'' stories, "Ayla and the Network". The ENTIRE plot is various groups having a [[Gambit Roulette]]. The winner is the one who can end the "I know you know" game. {{spoiler|It's Thuban and Ayla. Ayla, who knows people would break through any security she has, so BOTH her laptops are traps, and Thuban, who set up the ENTIRE blackmail plot!}}

* Experienced players in ''[[Mitadake High]]'' pull this kind of thing all the time when debating whether or not to give out their PDA Numbers. Unless the host has disabled the computers due to abuse, in which case there's no risk whatsoever.

** In some of the more complicated ''Mafia/Werewolf'' games, this can be a genuine issue. Oftentimes the evil team will have to deliberately and knowingly kill one of their own, because otherwise the good team will not only know that the person is evil, but that the other members of the evil team know that. It's now [http://mafiascum.net/wiki/index.php?title=Bussing common knowledge] that the evil team will do that, but it's still more effective than the alternative.

* [[Mind My Gap]]: Virgil Horn almost quotes this trope word for word on the [http://www.rostoad.com/map11.html loading screen].

== Real Life ==

* A semi-real life example, meaning it's actually an urban myth, is Winston Churchill's Coventry dilemma. Allegedly, Churchill had to allow the city of Coventry to be bombed, to prevent the Nazis from finding out about the British spies in Germany.

* When Alexander Litvenenko died, some of the speculation on who killed him got to this level. Welcome to the Cold War.

** CIA chief of counter-intelligence James Jesus Angleton spent the 60s and 70s turning the CIA upside down looking for a KGB mole. Some agents began to suspect that ''Angelton'' was a mole, on the grounds that starting a witch-hunt for a KGB mole is exactly the sort of thing a KGB mole would do.

* There is an active research field known as adversarial reasoning: essentially, building models that allow you to predict the actions of an adversary. Once the adversary happens to get a hold of your model it becomes rather useless, as he can make sure he does something other than what is predicted. So you simply create a new model - one that ''takes into account the fact that your adversary has the old model that he thinks tells him what you think he is going to do!'' The eventual end state is [[Gambit Pileup|left as an exercise for the reader.]]

* One classic example from the [[Second World War]]: an agent was sent to Great Britain by the Germans, who intended that the British intelligence service capture him and use him as a double agent, at which point he could tell the Germans how British counterintelligence functioned. He proceeded to explain this plan to the Brits, who then had him send back two different sets of reports to Germany. One contained what the Brits wanted the Germans to know; the other contained what the Brits wanted the Germans to think the Brits wanted them to know.

* Studies of animal intelligence sometimes use this trope as an analogy to model a species' cleverness in social interaction. Humans are the only species known to be able to do five levels of I/you know/think, while great apes seem able to manage four (e.g. they can bluff and ''be subtle about it'' so the other ape won't catch wise). Or the apes are [[Alternate Character Interpretation|far better at it]] than humans.

* The [http://terrytao.wordpress.com/2008/02/05/the-blue-eyed-islanders-puzzle/ Blue-Eyed Islanders puzzle] relies on this to an insane level, in that it ultimately depends on {{spoiler|a 100-story tall tower of hypotheticals. Let's say that K(0) is the knowledge that there exists someone on the island with blue eyes; and K(N+1) is the knowledge that everyone knows that K(N). So if I know K(1) it means I know everyone knows there's someone with blue eyes on the island; if I know K(2) it means I know everyone knows everyone knows there's someone with blue eyes on the island; and so on. The crux of the riddle rests on how, from being given ''K(100)'', everyone on the island deduces they have blue eyes by a mind-numbing 100-day process of collapsing hypotheticals}}.

** [[Fridge Logic|How is there both "no reflective surfaces" and "eye colors"?]] [[Take a Third Option|The liquid in eyes is reflective, just look into someone else's eyes and you'll find out what color it is.]] [[Completely Missing the Point|Well that was easy, onto the next logic puzzle!]]

*** Have you ever tried seeing the color of your own eyes in someone else's?

** The problem is enhanced by the possibility that the defenders may be intercepting and corrupting messages. If it's merely a question of messages getting through, sensible organisation should only require a couple of confirmations before further messages become irrelevant.

** More specifically, the practical solution is to evaluate the probability of success of a single message transmission, and to then repeat the transmission until the probability of failure has been reduced to a calibrated trivial percentage (say the message has a 1/10 chance of failing, then after sending it once you can be 90% sure that both generals have heard the message, after the first response it's up to 99%, then you might want to send a third one to bring it up to 99.9%, then stop if you can live with a one in a thousand chance of failure, or keep going if you can't).

[[Category:The Plan]]

[[Category:I Know You Know I Know]]