The “unusual 2NT” overcall of an opponent’s opening one-bid shows 5-5 or longer holdings in the two lowest unbid suits. Typically, it describes a “good-bad” hand of 6-11 or 16+ high-card points. With 12-15 HCP, players can naturally overcall in the higher suit, then bid the lower one.

Here are some sample uses of 2NT:

South                              West
1♠                                   2NT•

• 5-5 in clubs and diamonds

South                               West
1♥                                    2NT•

• 5-5 in clubs and diamonds

South                               West
1♦                                    2NT•

• 5-5 in clubs and hearts

South                               West
1♣                                    2NT•

•5-5 in diamonds and hearts

SouthWest

1NT2NT•

• 5-5 in clubs and diamonds

Now let’s deal with some 2NT hands:

South                               West
1♠                                     ?
♠10
♥9 4
♦A Q 9 6 5
♣ K 6 5 4 3

A bid of 2NT perfectly describes your minor-suit holdings. You should be conservative when vulnerable and aggressive when not. This hand works for both vulnerabilities. Don’t expect to bid again unless partner forces you to. Another sample:

South                               West
1♠                                    ?
♠10
♥4
♦A K Q 5 4
♣ A Q J 4 3 2

Bid 2NT and go to game in whichever suit partner names.

When you or partner responds to 2NT, which is forcing unless there has been an intervening bid by an opponent, the usual strategy is to take a preference on one of the two described suits. But sometimes the responder takes charge:

South            West            North               East
1♣                 2NT            Pass                  ?
♠6 5 4
♥Q J 10 9
♦K J 10 5
♣ 10 5

With help for the two lowest unbid suits, diamonds and hearts, cuebid 3♣ to ask about partner’s strength.

Another case study:

South            West              North               East
1♥                 2NT              Pass                  ?
♠6 5 4
♥10 9
♦K J 10 5 3
♣ Q J 5

Be aggressive against what may be superior competition and bid 4 ♦ pre-emptively. Suppose you have a better hand that merits a game bid:

South             West              North                East
1♥                  2NT              Pass                  ?
♠6
♥10 9
♦K J 10 5 3
♣ K Q 10 5 3

Bid 5 ♣. With as little as aces in the minor suits and a singleton heart, partner is worth raising to game.

The unusual 2NT not only disrupts opponents’ auctions but also can lead to some spectacular results when a player accurately gauges the four-hand layout. In this case, South was dealing, with both sides vulnerable:

NORTH
♠K 7 5
♥Q 9 8 3 2
♦A Q 8 4 2
♣ —

WEST                     EAST
♠ J 10 9 2               ♠ 6 4
♥ A K 4                  ♥ 10 7 6 5
♦ K 10 7                 ♦ 9
♣ K 10 7                 ♣ A Q 9 8 6 2

SOUTH
♠ A Q 8 3
♥ J
♦ J 6 5 3
♣ J 5 4 3

The bidding proceeded as follows:

South              West           North           East
Pass                 1♣            2NT              3 ♣
5♦!                 All Pass

Opening lead: ♥A.

How did South know to bid 5♦ in response to partner’s 2NT? By using deductive reasoning. First, the auction suggests that North has no clubs. Second, there won’t be more than one heart loser and possibly no spade losers. Finally, North-South have at least nine diamonds, almost certainly with two or more honors. Even if North is bidding a weakfish 2NT, go for it!

The contract will make against any defense.