There’s a pleasant sociable aspect to the online puzzle Wordle. Every day there’s a new word challenge, where you have to guess a new hidden five letter word. Every player has the same secret word to guess. So the puzzle encourages low grade rivalry and serves as a conversation starter amongst players — as long as the craze lasts.
Wordle was bought out by The New York Times who are well-placed to encourage micro-controversies. Last week the hidden word “caulk” promoted apparent concern: “what does it even mean!” complained some players, which is an unusual complaint from players with access to a web browser.
There are no initial clues to a Wordle puzzle, just 5 empty squares that you fill up with letters to make words. The game algorithm then highlights any letters that happen to be in the same place as in the hidden word. Those squares are coloured green. A square containing the letter that is in the word but in the wrong place is coloured yellow. Grey squares indicate that the letter you just entered is not in the hidden word.
The player then gets another 5 guesses taking account of the information supplied from the results of the first guess. Each attempt narrows down the options, but makes progressively more demands on the player’s vocabulary and recall.
Even 5 grey squares in the first row tells you not to use any of those letters in your second guess. That already reduces the search space. Of course, you are guessing five letter words, not random letter sequences. So it’s also a vocabulary test. It is more than likely that within the first three tries you’ll know the positions of some key letters, some candidate letters, and letters that are definitely not in the hidden word.
There are websites dedicated to calculating the odds of guessing the hidden word, and suggestions for optimising the player’s initial word choice. See https://artofproblemsolving.com/news/articles/the-math-of-winning-wordle. Much depends on common letter frequencies.
The challenge to discover a hidden word sounds cryptographic. Can you hide secret messages in a Wordle or a sequence of Wordle words? Here is a recent sequence of daily hidden Wordle words: CYNIC AROMA CAULK SHAKE DODGE. An imaginative conspiracy theorist might see covert messaging, but I don’t.
Paula Martínez provides a spreadsheet version of the Wordle program, so you can create your own hidden word Wordle puzzle. It’s not connected to a dictionary. So it doesn’t check that you are using actual words.
I hid four five-letter words to make up a plain text message. To make it look as though it’s hidden within a carrier message I could dispatch the sequence “ORDER PLONK WHILE SOBER”. But four blank words would be almost as easy as a starting condition: “_____ _____ _____ _____”. Here’s a reveal of my hidden (plain text) message.