Responding to 1NT

With a Balanced Hand

When your partner opens 1NT (12-14 HCP & Balanced Hand) and you also have a balanced hand, you will normally want to play in No Trumps.

To make Game in No Trumps you need to make 9 tricks (3NT) and normally hold 25+ combined HCP.

With 0-10 HCP you should Pass
Your side can not have more than 24 combined points which is normally insufficient for Game.
With 11-12 HCP you should bid 2NT
This is called an invitational hand inviting your partner to bid game if your partner holds the maximum points for their bid. In some circumstances if you hold 12 HCP and a hand with good features (see below) it is better to risk biding 3NT straight away.
- If the 1NT Opener has 12 HCP - They should Pass
- If the 1NT Opener has 14 HCP - They should rebid 3NT
- If the 1NT Opener has 13 HCP - They will Pass or rebid 3NT depending on the quality of their hand.
Good features would include:
- The prescence of a 5-card suit
- Having 9s and 10s rather than 2s or 3s.
Poor features would include:
- Having a suit such as KQ doubleton. This holding may only make 1 trick if your opponents hold the A. In effect 2 of your points are wasted.
- Flat hands with 4,3,3,3, shapes. These are usually more difficult to play in NT.

With an Unbalanced Hand

Less than 11 Points

With a weak hand and an uneven distribution containing a long suit, minimum 5-cards, you may wish to rescue your partner from 1NT into a more suitable suit contract. The opener must have at least two cards in your suit in order to have opened 1NT. You should rescue your partner even if you are very weak.

With a long suit in Diamonds, Hearts or Spades bid 2D, 2H or 2S.

You cannot rescue your partner by bidding 2C if your long suit is in clubs. This is because a 2C reply over a 1NT opening is reserved for the "Stayman" Convention (see below).

More than 11 Points - Holding a Major Suit

If you have 2 major suits or a 5+ card major suit and 11+ points you probably are strong enough to make a game if you have a suit fit with your partner. Use the Stayman Convention to investigate.

STAYMAN

Bidding 2C over your partners 1NT asks your partner to bid their 4-card major and implies that you have an Invitational hand and at least a 4-card major.

Your partner will respond:

2D with no 4-card major
2H with a 4-card Heart suit
2S with a 4-card Spade suit
With two 4-card suits bid 2H

Note: Bidding 2H does not deny a 4-card Spade suit but bidding 2S does deny a 4-card Heart suit.

Stayman can also be used over a 2NT opening.

More than 11 Points - No Major Suit

To make a game in a minor suit you need 28 to 29 combined points. If you have an unbalanced hand but with similar points to your partner (12-14 pts) you are unlikely to make a minor game and are better risking playing in 3NT.

Depending on your hand you can bid 3C or 3D to show your suit and let partner know that you are strong or bid 3NT directly. The advantage of bidding 3NT is that it does not give your opponents any information to find a good lead; the disadvantage is that you may miss a minor suit fit.