User:Brian/Bridge/Responding to a 1NT opening

Without interference

With minimal strength

I have one 5+-card major → Transfer to the major, then pass.

I have 5+ cards in both majors → Transfer to the better major, then pass.

Otherwise → Pass.

With invitational strength

I have a 6+-card major → Transfer to the major.

• If partner accepts by bidding 2 of the major (the most common case), rebid 3 of the major to invite. Partner will either pass or sign off by raising to the 4 level.
• If partner superaccepts by bidding 3 of the major, sign off by raising to the 4 level.

I have 5-5 in the majors → Transfer to hearts by bidding 2♦.

• If partner responds 2♥ (the most common case), rebid 2♠. Partner will either pass or sign off in 2NT, 3♥, 3♠, 3NT, 4♥, or 4♠, depending on their strength and distribution.
• If partner superaccepts by bidding 3 of the major, sign off by raising to the 4 level.

I have 5-4 in the majors → Bid 2♣ to ask partner for a 4-card major. This is called the Stayman convention, though the 5-4 case is not the usual one.

• If partner responds 2 of a major, raise to the 3 level to invite. Partner will pass or sign off by raising to the 4 level.
• If partner responds 2♦, denying a 4-card major, rebid 2 of your 5-card major. Partner will sign off in 2NT, 3M, 3NT, or 4M, again depending on strength and distribution.

I have a 5-card major → Transfer to the major.

• If partner accepts normally, rebid 2NT to invite. Partner may pass or sign off in 3M, 3NT, or 4M.
• If partner superaccepts, raise to the 4 level. Partner will pass.

I have at least one 4-card major → Bid 2♣, Stayman.

• If partner responds 2♦, denying a 4-card major, rebid 2NT to invite. Partner will pass or sign off in 3NT.
• If partner responds 2 of your major, raise to the 3 level to invite. Partner will pass or sign off by raising to the 4 level.
• If partner responds 2♥ and you have 4+ spades and 3- hearts, rebid 2♠. Partner will sign off in 2NT, 3♠, 3NT, or 4♠.
• If partner responds 2♠ and you have 4+ hearts and 3- spades, rebid 2NT. Partner will pass or sign off in 3NT.

Otherwise → Bid 2NT. Partner will pass or sign off by raising to 3NT.

With game-forcing strength

I have a 6+-card major → Transfer to the major by bidding 4 of the suit below the major. This is called a Texas transfer. Partner will accept the transfer by signing off in 4 of your major.

I have 5-5 in the majors → Transfer to spades by bidding 2♥.

• If partner accepts normally, rebid 3♥. Partner will sign off in 3NT, 4♥, or 4♠.
• If partner superaccepts, sign off by raising to the 4 level.

I have 5-4 in the majors → Bid 2♣, Stayman.

• If partner responds 2 of a major, sign off by jumping to the 4 level.
• If partner responds 2♦, rebid your 4-card major at the 3 level. This is called a Smolen transfer. Partner will sign off in 3NT or 4 of your 5-card major (to show 3-card support). Like the Jacoby transfer, the Smolen transfer ensures that the 1NT opener ends up as declarer.

I have a 5-card major → Transfer to the major.

• If partner accepts normally, rebid 3NT. Partner will pass or sign off at the 4 level.
• If partner superaccepts, sign off by raising to the 4 level.

I have at least one 4-card major → Bid 2♣, Stayman.

• If partner responds 2♦, denying a 4-card major, sign off by raising to 3NT.
• If partner responds 2 of your major, sign off by jumping to the 4 level.
• If partner responds 2♥ and you have 4+ spades and 3- hearts, rebid 3NT. Partner will pass or sign off in 4♥.
• If partner responds 2♠ and you have 4+ hearts and 3- spades, rebid 3NT. Partner will pass.

Jacoby transfer

The Jacoby transfer shows a 5-card major suit by bidding the suit below that suit. For example, if partner has opened 1NT, respond 2♦ to show 5 hearts, or 2♥ to show 5 spades. Your partner will then accept the transfer by bidding your suit (2♥ or 2♠, respectively). The point is to make partner mention the suit first so they end up as declarer, since they probably have the stronger hand.

Partner is obligated to accept the transfer, provided that the opponents don't interfere. This is the case even if partner only has two-card support. So for example, 2♦ forces a 2♥ response. The exception: if opener has a maximum and four-card support for your major, they will superaccept by bidding the major at the 3 level. So a 3♥ response to 2♦ is a superaccept, as is 3♠ to 2♥.