Signal (bridge)

In the card game of contract bridge, partners defending against a contract may play particular cards in a manner which gives a coded meaning or signal to guide their subsequent card play; also referred to as carding. Signals are usually given with the cards from the two-spot to the nine-spot. There are three types of signals:

The methods used for each type of signal have evolved over time and fall into two broad categories:

Partnerships decide on which methods to adopt and must disclose them to their opponents. Use and interpretation is dependent upon their context, i.e. the contract, the auction, the opening lead or prior play, the cards visible in dummy, the cards visible in one's hand, who has led to the current trick and whether following suit or discarding.

Accordingly, partnerships generally have an order of precedence for the interpretation of signals such as that indicated in the adjacent table. In the vast majority of cases, the third-hand follow-suit signal is an attitude signal, but when the attitude signal does not apply, it is a count signal. Usually, it is relatively easy to recognize a signal correctly when the declarer leads – either a count signal when following suit, or an attitude signal when discarding, and when they do not apply, it is a suit-preference signal.

While signals are a means of permissible communication between defenders, they are considered as providing guiding information to partner and are not absolutely binding on him; partner may proceed otherwise as he deems rationally appropriate. Because declarer is entitled to know the meaning of all partnership agreements, including defenders' signals, he also is privy to the information being exchanged; this may give way to falsecarding tactics by the defenders.

When signaling standard attitude, a high card is encouraging and a low card is discouraging. Attitude is normally signaled when following suit to partner's led suit and when discarding on either partner's or declarer's led suit.

For example, if partner leads the Ace of spades, you might signal with the nine if you held the King (requesting partner to continue the suit), or with the three if you held nothing but small cards in spades (notifying partner that a switch to another suit is likely best).

Of course, you can only signal with the cards you hold. Signaling low is easy for you, but if your lowest card is the eight, partner might have difficulty "reading" it as low. When you are signaling high, play the highest card you can afford. Having easily readable cards to signal with is part of the luck of the deal.

Suppose declarer is drawing trumps and you are out on the third round. Your discard should be an attitude signal for partner. If you play a high diamond, for example, you ask partner to lead diamonds if she should gain the lead. Normally, you would have an honor or honors in diamonds in this case. If you play a low diamond, you ask partner to not lead diamonds if she should gain the lead. Partner will usually be able to figure out which of the other suits you do like (if any).

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Wikipedia