Contract Bridge is a game with a supposedly high ethical standard. Though it is played mainly for glory or honor and occasionally for dollars and cents, there is opportunity for deception, lying, and outright guile. There are, however, certain actions that are in bad form at the table. These include: talking during the bid or play of the hand (known as coffee housing); gloating or snickering; and leaving the room without permission. Falling asleep or dying during the play is also discouraged. Watching TV, eating a large meal, or using a cell phone is blatantly poor etiquette. 
        Bridge has written and unwritten moral codes that all good players should make an effort to observe. We should try to control any extraneous gestures or vocal tonalities that convey information to our partner (such as standing on the chair and yelling "DOUBLE!!"). Use of private signals is outright cheating and is not to be tolerated. If you happen to use such signals during a high stake money game and are discovered, you might discover that your nose has moved to the side of your head. But in spite of all these restrictions and caveats, there is a place in Bridge for the inveterate liar and dissembler. 
        Who can I deceive? Good question. Possible answers: the IRS, my wife, my Bridge partner (who may also be you wife). But watch it. If something goes wrong it could mean jail, divorce or playing in a vulnerable doubled/redoubled contract with only 5 trumps. (The penalty could be a little higher than the last four digits of your Social Security number.) So it is important to make sure that the consequences of your chicanery can do no harm. The ideal time to employ deception is when your partner is the Dummy. (Kibitzers can also safely be deceived . . . but only if they really want to.) 
        When you are Declarer and partner is Dummy, you can deceive your opponents at will. Nothing bad will happen - to you; the sky will not fall down. But to get results your opponents have to be members of the AAA: Awake, Aware, Alert. You can never hoodwink someone who is brain dead or approximates brain deadness. It is the experts, or so called experts, that watch the spots on the cards that are the best candidates for your Big Bridge Sting. The beginner or novice will ignore your tricky ploys and not be taken in by the con. The better your opponents, the better the chances of getting good results by deception. Let us now see what deceptive tactics are at our disposal.

We have choices in life, and often these choices effect the outcome of certain events. What card you play or do not play can cause your opponents to make choices that can be in your favor. False-carding is playing a card you would not normally play - but will not cost anything - and can snare your opponents into making the wrong decision. Some counter intuitive action is usually involved. Here is a typical example of false-carding.  Contract is 4 S.

S  Q 8 7 6
H   J 5 2
D  Q 8 7
C  A Q 4

S  K J 10 5 4 3
H  Q 8
D  K 9 2
C  K 7

West leads the A H. The defenders are on the verge of taking two Hearts, the A S (always a winner) and the A D for down one. How can you stop West from leading the second Heart (K H)?  Spilling hot coffee on his lap might hurt enough for him to forget Hearts and switch to a Club. Nice try, but there is another way. On the opening lead of the A H you play the 2 H from Dummy; wait for your right hand opponent to  play a card; and then without  hesitation, no guilty looks, but very naturally table the Q H from your hand. This Q H is a false-card. You would normally play the 8 H. This little piece of dissembling give the impression that the Q H is a singleton; that you will trump the next Heart lead. Also note that this play is a freebee, it costs the Declarer nothing. Now West starts to think. (Could be a dangerous activity for some and  painful for others.) What good player in his or her right mind, and there are a few, would now lead the K H? It will get trumped by Declarer and the J H in Dummy will now become a winner. 
        At trick two West switches to a Club. Win the K C in your hand and play the 7 C to Dummy's Ace. Now for the coup de false-card. Play the Q C and dump your Heart loser (8 H). The final results: you lost a Heart (A H) at trick one; you will lose the Ace of trumps ( A S); and the A D. You lost three tricks, made 10 and made your contract of 4 H. What have we learned from this hand? One - never give up. Two - expect the unexpected. Three - think and strategize before playing the first card. And four - never miss an opportunity  to  swindle your opponents.