Right, I am very sorry to have to do this, and will get downvoted into oblivion guaranteed. But I am here to expose Mornington Crescent. I have never ever seen it explained anywhere because it would ruin the game - but not in the same way as it would ruin Mao. Mornington Crescent is ostensibly the same as Mao but in reality they are totally different. Mao is a real card game with a set of rules. However those rules have to be worked out by the players as part of the game. See the Mao writeup for more details.

Mornington Crescent has NO rules. It is not a game. All it is is a framework for taking the piss out of people who do not know this, by those who do. Typically a game is started at a party (or in the Chatterbox) with a mix of people. Some know the 'rules' and so participate whilst the rest are convinced to play. The players then start naming stations on the London Underground the aim being to reach Mornington Crescent. When someone who knows says a station the others who know nod sagely and say things like "ahh, good move" or "hmm, using the yellow line, is that allowed?". Players who don't know try and fathom what is governing the moves. Of course nothing is governing the moves - it is all an elaborate ruse. When someone not in the know says a station someone might mutter "beginner's luck" or "How did you know about the Kafinikov variation?" throwing the player into further confusion. Equally if the player tries to go straight to Mornington Crescent they will usually be berated with a "going to Mornington Crescent from there, on a Tuesday, with the flange rules in play - I don't think so!". Of course all of this is made up on the fly - the only intention being to confuse.

I think this 'game' is cruel and unfair, especially when used on Americans. It is only fun to 'play' if you like systematically ridiculing people, which I personally don't. People will also probably add writeups here saying I am wrong or don't understand to try and successfully cover up the truth. These people are lying to you!.

Remember: The truth is out there

I will heroically absorb the downvotes that are already mounting in the name of freedom of information. :)

tardibear: I completely agree with you (except there are no rules - not even internally consistent ones within a given game - unless you have been playing it wrong :)). My WU may be a bit harsh, but very few people, if any, play with only people who know about the game. The idea is to befuddle. That is all I wanted to be known. Introducing new players does involve this - no one ever get's told what I have noded above, it wouldn't work if they did. When people look up the rules to Mornington Crescent they deserve to get them, not just an extension of the game being played out on E2.