The object of the game is to be the only one who can complete a word without getting caught bluffing.
You take turns adding one letter at a time to the beginning or end of a set of letters. If at any time, you think your friend cant come up with a word that contains those exact letters in that order somewhere in the word, call their bluff!
Then they get to wow you with their masterful vocabulary by telling you the word, or forever be known as a Word Bluffer.
Try different strategies by playing sets of letters that show up in different words to give yourself more options. Or back your opponent into a corner by strategically using -ing -ly -ed or -s to force them to bluff.
Cant think of a word with those letters or dont think you can play a valid word? Well...it is called Word Bluffer for a reason.