Responses and Later Bidding after a 1♥ or 1♠ Opening

1♥ and 1♠ openings show a five-card or longer suit. Responses:

1♥	1♠	At least four spades, 6 or more points. Tends to deny a heart fit.
	1NT	6-10 points, denies four spades or three hearts. NOT forcing.
	2♣, 2♦	11 points or more, promises at least four of the suit.
	2♥	three-card or longer heart support; 6-10 dummy points.
	2NT	Game-forcing raise ("Jacoby 2NT"), 13+ dummy points. Asks opener to show a short suit to help responder evaluate slam prospects. (See below for other responses).
	2♠, 3♣, 3♦	strong jump shifts. Invite a slam.
	3♥	limit raise (10-12 dummy points with three or more hearts. It might be better, however, to bid 1NT with only 10 points, weak 3 card support, and a balanced hand).
	3NT	15-17 HCP, balanced hand with two-card support for partner (since this bids crowds the auction, consider it only if hand is ideal for 3NT, i.e. no honors in partner's suit and/or lots of J and Qs rather than A and Ks)
	4♥	usually 5+ hearts, a singleton or void, and fewer than 10 HCP

Opener's rebids are natural and standard.
Rebids with a minimum hand (13-16 points):

• Rebidding notrump at the cheapest available level;
• Raising responder's suit at the cheapest level (this can be done with good three-card support if desired);
• Rebidding a new suit (but not reversing);
• Rebidding opener's suit at the lowest level.

After a two over one some of these responses can create a conflict with responder's obligation to make a rebid. Essentially this means that 2NT and raising partner's suit are forcing. Some pairs resolve this by requiring that 2NT and raising responder's suit (minor) show at least a little extra strength. Without extra strength these pairs rebid the suit opened which does not therefore promise extra length.

Others resolve these issues by allowing 2NT and a simple raise by opener to be passed. In any case this issue needs careful attention by a serious partnership.

Rebids with a medium hand (17-18) points:

• Jump raise or jump rebid of opener's suit;
• Reverse in a new suit
• Non-reverse bid in a new suit (this has the wide range of 13-18 points).

A reverse is a bid in a higher ranking suit at the two-level. It always shows greater length in the first bid suit and extra strength. A reverse is forcing for one round.

With a maximum hand (19-21 or 22 points) opener must make a very strong rebid:

• Jump in notrump;
• Double jump raise in responder's suit or double jump rebid of opener's suit;
• Jump shift in a new suit.

If responder jumps to 2NT over a 1♥ or 1♠ opening, that is Jacoby 2NT, asking opener to show a singleton or void. If opener has no short suit, he shows his hand strength in reverse order - lowest bid shows the strongest hand giving more bidding room for slam exploration;

1♥	2NT
	3♣, 3♦, 3♠	Singleton or void in that suit
	3♥	maximum hand (18+) no shortage
	3NT	medium hand (15-17) no shortage
	4♥	minimum hand no shortage

Responder follows up by attempting to sign off in game, bidding 4NT Blackwood, or cuebidding if still interested in trying to cooperate with opener in making the slam decision.