A Scrabble bluff will often be most successful if it's part of a larger defensive strategy, like knowing which letter tiles an opponent might have in their rack and where on the board they're likely to play next. If you play a nonsense word that blocks an opponent's next likely move, he's probably going to be thinking more about reformulating his strategy than challenging your word. You'll need to know how many total tiles are available for each letter, and then track which ones you've played, which ones your opponents have played -- and which tiles must therefore be left.
Although this sort of defense sounds a lot like counting cards (something that's usually considered cheating in card games), the boundaries are different for Scrabble: Counting tiles is acceptable during competitive play. Still, it's important to distinguish between bluffing and making a move -- like secretly swapping out undesirable letters for better ones from your pocket -- that hits below the belt. Cheating runs counter to the rulebook, but bluffing doesn't.
Take psychological bluffing strategies, for example. Use your tiles to spell out real but unlikely words, like apatite (a mineral) or dornick (a stone small enough to throw). Keep it up, and sooner or later your opponent will challenge your words. Then you can simply point them out in the dictionary and your opponent will lose a turn. And you'll have effectively set the stage for strategic bluffing. Now you can play made-up words at will, knowing your opponent probably won't risk challenging them and losing another turn [source: Meyers]. As a bonus, your opponent will spend time thinking about you, your tiles and the tiles you've played instead of how he'll play his own tiles -- thus giving you an even greater psychological advantage.
One of the keys to a successful bluff is the ability to sell it. Act with utter confidence and you'll be off to a good start. For example, use your areas of expertise -- whether they're part of your career, hobby or education -- when making word selections. Let's say you're really into metallurgy (the study of metallic elements and compounds). Regale your opponent with your knowledge on the subject, and then play fake or purposefully misspelled words, perhaps aneal or quinch, that are presumably from your jargon-rich vocabulary. When asked for a definition by your opponent, you can easily produce one -- for a real word.
Once you've made a few successful smoke-and-mirror moves, concentrate on tile placement. Close off the board by making parallel plays, stretch your words into double- and triple-point squares and use as many seven-letter words as possible to gain 50-point bonuses. Before you know it, you may just bluff your way to a win [source: Shah].