I have included this as it is an absolute classic but not suitable for anyone who does not know the London tube map, or indeed anyone who does not already know the rules.
As far as I know, this game was invented by the brilliant BBC Radio 4 panel show I’m sorry I haven’t a clue.
Each player takes it in turn to say a London Underground station name. The game is ended when a player says ‘Mornington Crescent’.
The point of the game is there are no rules. The trick is to improvise by making it sound like a real game with rules that can be disputed and it can be very funny, if you act it out as if you did know the rules based on the previous station or other parameters.
There are various other on-line and published resources available of varying quality. As such the game Mornington Crescent is satire of other games.
We have adapted this game (as ever) as it was totally beyond the kids. The alternative we used was similar to word tennis- you choose a category e.g. fruits, Harry Potter characters (that old favorite), breeds of dog, Thomas the tank engine characters, dinosaurs or whatever suits your family.
Then one player whispers any word, in the category, which becomes the word that will end the game to another player. ‘Banana’ if the category is fruits, for example. The other players must hum or sing so they don’t hear the whisper. Then the remaining player play word tennis in the category until one says the word in question. S/he is the winner. Simple!