The defenders use the same techniques as declarer to develop tricks: promotion, length, finesse, trumping, and discarding losers on winners. Because they can’t see each other’s cards, they need to help each other with defensive signals.
It’s acceptable to show partner by the card you play whether you like the suit led. Provided you can’t win that trick (and winning the trick is your first priority), show partner your attitude to their lead.
Decide whether to play low or high encouraging signals. This means (if low to encourage), the smallest card you can afford will tell partner you liked the lead, and most importantly, you would like that suit continued. High is the opposite – the highest card you can afford says you liked the lead. Make sure you and partner are on the same page with this! NB: The person who leads simply follow the recommended lead guidelines (See Lesson 1 Opening Leads). It’s the leader’s partner who signals their “attitude” to the lead.
Lead from partner: ♥3
Dummy (the next hand to play)
Partner leads the ♥3, dummy wins the ♥A, and you have ♥K92. You would like hearts continued, hoping to win your ♥K
Playing low encouraging, the correct card to play is the ♥2.
Playing high encouraging, it’s the ♥9.
Partner will expect an attitude signal when you can’t win the first trick, and on your first discard too.
Count: Sometimes it might be better to show partner how many cards you hold, instead of whether you like a suit and want it continued. This occurs when declarer is playing their long suit. Perhaps partner holds the ace and wants to break communications with dummy by taking their ace only when they know declarer will have none left to cross to dummy.
Play high-low to show an even number of cards, and low-high to show odd. Eg you hold 9853. Play the 9 followed by the 3, to show four (or two) cards. If holding 983, play the 3 first, followed by the 9, to show 3 (or 5) cards. It’s important to recognise when the situation calls for attitude or count. Attitude should have priority, and count only when attitude doesn’t apply.
Suit Preference: Sometimes your partner needs to know how to reach your hand later in the play, i.e. where’s your entry. This is important when giving partner a ruff or to know how to reach partner’s hand when playing your long suit at no trumps. The card you play will ask partner to return either the higher-ranked suit, or the lower-ranked suit.
The play of an unnecessarily high card asks for the higher ranked suit to be returned, and a low card asks for the lower suit. (McKenney and Lavinthal are suit preference signalling methods).