Lightner Double: The Slam Double That Asks for a Lead

A Lightner double is a double of the opponents' freely bid slam by the player who is not on lead, asking partner for an unusual opening lead. It is not a penalty double based on trump tricks. It says "do not make your normal lead", and most often it asks for the first side suit bid by dummy. The doubler usually has a void and wants a ruff, or a strong holding such as A-Q sitting over dummy's king.

The convention is named after Theodore Lightner, who described it in 1929, and it is the default meaning of a slam double in 2/1, SAYC and Acol unless a partnership agrees otherwise.

When partner doubles a slam, go through these rules in order:

1. Do not lead trumps.
2. Do not lead a suit your side has bid. If partner bid a suit and still doubles, the double says "not my suit". If you bid a suit, the double also says "not yours".
3. Do not make the obvious lead in an unbid suit. That is the lead you would make without the double.
4. Lead dummy's first-bid side suit if dummy bid one. This is the most common meaning.
5. If dummy bid no side suit, look for the most unusual lead left, often a suit that declarer bid.

Your own hand is the best clue. If you hold five cards in dummy's suit, partner is very likely void in it. If you hold only two or three small cards in dummy's suit, partner may instead hold a tenace such as the A-Q over dummy's king and want a lead through dummy.

The scoring makes a penalty double of a slam a poor bet. With six of a major:

If the slam is going down, the double gains only 50 or 100. If they make it, the double costs 230, and a redouble or a run to a safer slam costs even more. So the double is far more useful as a message: it finds the lead that turns a making slam into a failing one, a swing of more than 1,000 points.

If you hold two aces, do not double: the slam is already going down. A double would only send partner on a strange lead, which might give declarer the twelfth trick.

You are South with no high cards at all. Without the double you would lead partner's suit, a heart. But partner, who bid hearts, doubled a slam: by Lightner, that says do not lead a heart. Dummy's first-bid suit is diamonds, and you hold five of them, so partner is surely short. You lead a diamond.

Reveal the full deal. North is void in diamonds: he ruffs the opening lead and cashes the ♥A. 6♠ doubled goes one down.

Double dummy, the lead decides everything:

The double turned -980 into +100. There is one cost to accept: East could escape to 6NT, which also takes twelve tricks double dummy, because there is no ruff in notrump. That risk is the price of every Lightner double.

Now sit in the doubler's chair. You double a slam when one specific lead beats it and partner will not find that lead on his own. The common hands:

• A void in dummy's side suit, plus a likely trick elsewhere. The example above: ruff the lead, cash an ace.
• A-Q or K-J over dummy's king or queen. If dummy bid clubs with ♣K-x-x-x and you hold ♣A-Q-x behind it, a club lead gives you two tricks at once; any other lead lets declarer discard his clubs on another suit.
• A trick that has to be set up before declarer gets going. With a sure ace and a king that needs a lead through declarer, the double can ask for that suit.

Do not double when you have nothing but a vague hope, when partner's normal lead is probably right anyway, or when the opponents have a safer slam to run to. A double that sends partner on the wrong lead can give away a slam that was going down.

If they redouble, the message stands: partner still leads the unusual suit. A redoubled slam that goes one down is worth +200 not vulnerable, so the cost of being wrong goes up, but so does the gain.

Not every Lightner double is about a ruff. Picture this auction: East opens 1♠, West responds 2♣ (game forcing in 2/1), and they bid to 6♠. Partner doubles. You hold ♠83 ♥QJ104 ♦9762 ♣754.

The normal lead is the ♥Q, top of your sequence in an unbid suit. The double says no. Dummy's first-bid suit is clubs, so you lead a club. Your three small clubs make a club void less likely, so he more likely holds a strong club holding, such as the ♣A-Q sitting over a king in dummy. Your club lead traps that king before declarer can draw trumps and discard his losing clubs on dummy's hearts or diamonds, and the defense takes two club tricks at once.

You do not need to know which pattern partner has. You only need to follow the rule, and partner has done the thinking for you.

A double of a 3NT game by the player not on lead is also lead-directing, but it asks for a different suit. The common agreement:

• If the doubler bid a suit, lead it, even with a single card.
• If the opening leader bid a suit, the double says "lead your suit", even if it is weak.
• If neither of you bid, the double usually asks for dummy's first-bid suit, where the doubler has a strong holding.

Against 3NT the doubler wants his own long suit or a suit he can run, not a ruff. For the normal leads against notrump, see what to lead against 3NT.

• When your side has sacrificed or bid to a high level and the opponents then bid slam, some pairs play a double as penalty. Agree it.
• Against a grand slam, the same rules apply. A double of a grand slam asks for an unusual lead, often dummy's first-bid suit.
• When the doubler is on lead, a double has no lead to direct. It is then simply a penalty double.

Agreements vary at the edges, but the core rule is the same in every system: a double of a freely bid slam by the player not on lead asks for an unusual lead. You can compare how each system reads a double of a slam.

To train the opening lead itself, play hands in the Lead Gym or solve opening lead puzzles. For the general lead rules, see opening leads and opening leads against suit contracts. The other doubles you will meet are in doubles in bridge, and slam bidding shows the auctions from the other side.