In Scrabble, a phoney is any word that is not listed in the dictionary being used (the OSPD, the OSW, SOWPODS, &c. &c.). In Scrabble notation, a phoney is designated by a * (e.g., NODER*). The strategies surrounding when to play phoneys, and when to challenge your opponent's, has been the subject of much discussion by Scrabble experts.

Phoney FAQ

Q. What do you mean, "when to play phoneys"? Isn't playing phoneys against the rules?

A. Nope. According to the National Scrabble Association's official tournament rules, phoney words will only be removed from the board if they are challenged and ruled unacceptable. If no challenge is made that turn, the phoney word or words remain on the board for the remainder of the game.

Q. So you could play a word, knowing that it was a phoney, and it would count if your opponent doesn't challenge it? That's dishonest!

A. Not really a question, but I'll allow it. This is a perfectly valid concern, and is indicative of the rift in mindsets between casual, just-for-fun players—known semi-perjoratively as "living-room players"—and hardcore tournament players. It's perfectly acceptable, in living-room play, to use only words that everyone knows the definition of, to bingo only once every fifty turns or so, to be comfortable with scores in the low 200s. But you should know that out in the tournament scene, it's an entirely different game—a game where players have memorized every four- and five-letter word in the dictionary, where people write pages of complex analysis on a five-point endgame play... and where playing a phoney is just another strategic maneuver that can win you games.

Q. Well, fine. So how do I do it?

A. You were saying a minute ago that it was dishonest.

Q. I'm asking for, uh, a friend.

A. Right. Anyway, Everything Scrabble, the indispensible strategy book by Joe Edley and John D. Williams, advise several situations in which playing a phoney might be a good idea:

  1. Nothing to lose. If you're down by 150 points in the middlegame, and you see a place to play a high-scoring "almost word," you might as well. If you can get (say) PARTERS*, UNCARED*, or PARODIZE* by your opponent, it could make the difference in the game. And if it gets challenged off the board, you're no worse off than you were before.
  2. Testing the waters. If you have the first move against someone you've never played before, and you don't have a grand slam of a word sitting on your rack, there's no good reason not to play an okay-looking phoney, to see what your opponent will do. If the word stays on the board, this will give you some idea about your opponent's knowledge of the dictionary, and you can act accordingly. If, however, you draw a challenge, you've lost nothing but the first move.
  3. One-two punch. Suppose you've just played NICKLES. Your opponent, smugly sure that you've transposed the L and the E, challenges it. Surprise! it comes back acceptable, and it's your turn again. If you now play a good-looking phoney, your opponent may let it go, afraid of losing two turns in a row.
  4. Small potatoes. It can also be to your advantage to play a plausible phoney that scores 10 to 20 points when the play would leave you with a much better rack and you have no great plays. Such a play might not end up drawing a challenge, because your opponent might assume that you wouldn't risk drawing a challenge and losing a turn for such a small amount of points. This one is trickier, but still entirely possible.
  5. First-round KO. If you have a moderately sized lead, and you see an opportunity to bump your lead up to 100 points or more with a phoney bingo, go for it! Especially in the middlegame, where the outcome has yet to be decided, a decisive, 150-point lead can demoralize an opponent. And if the word gets challenged, then you still have the lead.

Q. Fascinating! But let's turn it around now. Let's say I think my opponent is doing one of these things. I should challenge, right?

A. Well, usually. If you're sure that it's a phoney, you should always challenge... unless it's to your advantage not to. Consider:

  
   a b c d e f g h i j k l m n o
   -----------------------------
 1|=     '       =       '     =|
 2|  -       "       "       -  |
 3|    -       '   '       -    |
 4|'     -       '       -     '|
 5|        -           -        |
 6|  "       "       "       "  |
 7|    '     B E A T       '    |
 8|=     F E I N T       '     =|
 9|    ' r     '   '       '    |
10|  "   U   "       "       "  |
11|      G -           -        |
12|'     A               -     '|
13|    - L     '   '       -    |
14|  -   E   "       "       -  |
15|=     R       =       '     =|
   ----------------------------- 
    Your rack: AAEEGSV
    
    you: 17    opp: 24 (98?) 

Your opponent has just bingoed with FrUGALER D8 74. Do you challenge? The word makes sense—if you can be frugal, there's no reason someone else can't be frugaler. Your opponent could have made any number of other bingos (GRAtEFUL, rEGULAR) that would be safer. But wait! Look at your rack! If you don't challenge FrUGALER, then it allows you to play a triple-triple for 158 points. What is it? (Answer in this pipelink.)

Of course, the answer won't always be that simple. Usually, the best tools are your own intuition and your knowledge of your opponent's playing style. Does your opponent play phoneys often? How much do you know about your opponent's sophistication, or word knowledge? Do you detect any of the phoney-playing tricks listed above? All these, more often than not, will be your guide to whether or not to challenge.

Q. Neat-o! Where can I learn more?

A. An excellent resource, as I said, is Everything Scrabble, by Joe Edley and John D. Williams, published by Pocket Books (from which the FrUGALER example was shamelessly stolen, by the way). But the best resource is experience! Play whenever you can, hone your intuition, learn as many words as you can, and you'll be on the road to playing phoneys like a pro.