Ghost is a classic word game wherein one player provides a starting letter, the other adds a letter, and so on until either player completes a word, or one player challenges the other, claiming that the sequence so far is part of no legal words. A variant, Superghost, allows for letters to be added to either the start or end of the existing sequence. The game is described in its Wikipedia article, and James Thurber wrote about Superghost for The New Yorker with his essay "Do You Want to Make Something Out of It? (Or, if you put an "o" on "understo," you'll ruin my "thunderstorm")"